Meaning: Unable to be placated or appeased; relentless.

Part of speech: adjective

Example: The implacable enemy refused to negotiate.

Category: Psychology

Synonyms:

• unyielding
• inflexible

Antonyms:

• yielding
• flexible

Meaning: To insert or fix something firmly into a substance.

Part of speech: verb

Example: Doctors implant devices to help patients.

Category: Medicine

Synonyms:

• insert
• embed

Antonyms:

• remove
• extract

Meaning: Not seeming reasonable or probable; unlikely.

Part of speech: adjective

Example: His explanation was implausible.

Category: Science

Synonyms:

• unlikely
• incredible

Antonyms:

• likely
• plausible

Meaning: To show that someone or something is involved in a crime or wrongdoing.

Part of speech: verb

Example: The evidence may implicate several suspects.

Category: Law › Criminal Law

Synonyms:

• involve
• entangle

Antonyms:

• exonerate
• absolve

Meaning: Involved in a crime or wrongdoing.

Part of speech: adjective

Example: The implicated individuals were arrested.

Category: Law › Criminal Law

Synonyms:

• involved
• entangled

Antonyms:

• exonerated
• absolved

Meaning: A conclusion that can be drawn from something, although it is not explicitly stated.

Part of speech: noun

Example: The implication of his words was clear.

Category: Communication

Synonyms:

• inference
• suggestion

Antonyms:

• explicitness
• clarity

Meaning: Implied or understood though not directly expressed.

Part of speech: adjective

Example: There was an implicit agreement between them.

Category: Communication

Synonyms:

• implied
• unspoken

Antonyms:

• explicit
• stated

Meaning: To collapse inward violently.

Part of speech: verb

Example: The building will implode in a controlled demolition.

Category: Science

Synonyms:

• collapse
• cave in

Antonyms:

• expand
• inflate

Meaning: To beg someone earnestly or desperately to do something.

Part of speech: verb

Example: She implored him to stay.

Category: Communication

Synonyms:

• beg
• plead

Antonyms:

• demand
• insist

Meaning: Showing earnestness or desperation in requesting something.

Part of speech: adjective

Example: His imploring eyes made her feel guilty.

Category: Communication

Synonyms:

• pleading
• entreating

Antonyms:

• indifferent
• unconcerned

Meaning: Difficult or impossible to estimate or measure.

Part of speech: adjective

Example: The imponderable nature of the universe fascinates scientists.

Category: Science

Synonyms:

• unmeasurable
• inestimable

Antonyms:

• measurable
• quantifiable

Meaning: Persistent, especially to the point of annoyance.

Part of speech: adjective

Example: The importunate salesman wouldn't take no for an answer.

Category: Business

Synonyms:

• insistent
• demanding

Antonyms:

• unassertive
• submissive

Meaning: To ask someone persistently and urgently.

Part of speech: verb

Example: She importuned him for help.

Category: Communication

Synonyms:

• beg
• urge

Antonyms:

• dissuade
• discourage

Meaning: A person who pretends to be someone else in order to deceive others.

Part of speech: noun

Example: The impostor was caught trying to steal the identity.

Category: Communication

Synonyms:

• fraud
• fake

Antonyms:

• genuine
• authentic

Meaning: The inability to take effective action; powerlessness.

Part of speech: noun

Example: His impotence in the situation frustrated him.

Category: Psychology

Synonyms:

• powerlessness
• helplessness

Antonyms:

• power
• strength

Meaning: Lacking power or ability.

Part of speech: adjective

Example: He felt impotent in the face of the crisis.

Category: Psychology

Synonyms:

• powerless
• helpless

Antonyms:

• powerful
• capable

Meaning: To seize and hold something, especially by legal authority.

Part of speech: verb

Example: The police can impound vehicles for various violations.

Category: Law

Synonyms:

• seize
• confiscate

Antonyms:

• release
• return

Meaning: To make someone or something poor.

Part of speech: verb

Example: The war will impoverish the nation.

Category: Economics

Synonyms:

• deplete
• reduce

Antonyms:

• enrich
• improve

Meaning: The state of being poor or impoverished.

Part of speech: noun

Example: Impoverishment can lead to social issues.

Category: Economics

Synonyms:

• poverty
• deprivation

Antonyms:

• wealth
• prosperity

Meaning: Not feasible or practical.

Part of speech: adjective

Example: The plan was deemed impracticable.

Category: Business

Synonyms:

• unfeasible
• impossible

Antonyms:

• feasible
• practical

Meaning: Not sensible or realistic; not practical.

Part of speech: adjective

Example: The idea was impractical for everyday use.

Category: Business

Synonyms:

• unrealistic
• impossible

Antonyms:

• practical
• feasible

Meaning: A spoken curse or invocation of evil.

Part of speech: noun

Example: He uttered an imprecation against his enemies.

Category: Religion

Synonyms:

• curse
• malediction

Antonyms:

• blessing
• benediction

Meaning: Not accurate or exact.

Part of speech: adjective

Example: His imprecise measurements led to errors.

Category: Science

Synonyms:

• inaccurate
• vague

Antonyms:

• precise
• exact

Meaning: The quality of being inaccurate or vague.

Part of speech: noun

Example: Imprecision in data can lead to faulty conclusions.

Category: Science

Synonyms:

• inaccuracy
• vagueness

Antonyms:

• precision
• accuracy

Meaning: Unable to be captured or broken into.

Part of speech: adjective

Example: The fortress was impregnable against attacks.

Category: Military

Synonyms:

• invulnerable
• unassailable

Antonyms:

• vulnerable
• assailable

Meaning: To make pregnant; to fertilize an egg.

Part of speech: verb

Example: The male animal can impregnate the female.

Category: Biology

Synonyms:

• fertilize
• inseminate

Antonyms:

• sterilize
• infertile

Meaning: A person who organizes and often finances concerts, plays, or operas.

Part of speech: noun

Example: The impresario arranged a grand performance.

Category: Arts

Synonyms:

• producer
• organizer

Antonyms:

• performer
• artist

Meaning: Easily influenced because of a lack of critical ability.

Part of speech: adjective

Example: Children are impressionable and can be easily swayed.

Category: Education

Synonyms:

• susceptible
• influencable

Antonyms:

• resistant
• unimpressionable

Meaning: Official approval or permission, especially in publishing.

Part of speech: noun

Example: The book received the imprimatur from the publisher.

Category: Business › Publishing

Synonyms: approval

Meaning: To call into question; to challenge the truth of something.

Part of speech: verb

Example: She did not want to impugn his motives.

Category: General

Synonyms:

• challenge
• question

Meaning: Exemption from punishment or freedom from the injurious consequences of an action.

Part of speech: noun

Example: He acted with impunity, knowing he wouldn't be caught.

Category: Law

Synonyms: exemption

Meaning: To attribute or ascribe something to someone.

Part of speech: verb

Example: He did not want to impute blame to anyone.

Category: General

Synonyms:

• attribute
• ascribe

Meaning: In an extreme or critical situation.

Part of speech: phrase

Example: He acted in extremis to save the child.

Category: General

Meaning: lower in rank or position

Part of speech: adjective

Example: He felt subordinate to his boss.

Category: Business

Synonyms:

• inferior
• secondary

Antonyms:

• superior
• dominant

Meaning: Not allowed or accepted.

Part of speech: adjective

Example: The evidence was ruled inadmissible in court.

Category: Law

Synonyms: unacceptable

Meaning: Not able to be taken away or transferred.

Part of speech: adjective

Example: The right to free speech is considered inalienable.

Category: Law

Synonyms: untransferable

Meaning: Unable to express oneself clearly.

Part of speech: adjective

Example: He was inarticulate when asked about his feelings.

Category: General

Synonyms:

• tongue-tied
• uncommunicative

Antonyms: articulate

Meaning: To the extent that; in view of the fact that.

Part of speech: conjunction

Example: Inasmuch as he was late, we started without him.

Category: General

Meaning: Not conducive to success; unpromising.

Part of speech: adjective

Example: The rain on the wedding day was seen as inauspicious.

Category: General

Synonyms:

• unfortunate
• unlucky

Antonyms: auspicious

Meaning: Resulting from inbreeding; having a narrow genetic diversity.

Part of speech: adjective

Example: The inbred population showed signs of genetic disorders.

Category: General

Synonyms: interbred