Vocabulary and Synonyms

Implausible means not seeming reasonable or probable; failing to convince. Doubtful is a synonym as it implies lack of conviction or probability.

Importune means to ask someone pressingly and persistently for or to do something. Harass is a synonym as it involves persistent annoyance or pressure.

Impromptu means done without being planned, organized, or rehearsed. Extempore is a direct synonym meaning spoken or done without preparation.

Inarticulate means unable to speak distinctly or express oneself clearly. Faltering is a synonym as it describes hesitant or unclear speech.

Indecorous means not in keeping with good taste and propriety; improper. Inappropriate is a direct synonym.

Incipient means in an initial stage; beginning to happen or develop. Developing is a synonym.

Importunate means persistent, especially to the point of annoyance or intrusion. Insistent is a synonym.

Impiety means a lack of respect for God or religion. Blasphemy is a synonym as it refers to the act of insulting or showing contempt for God.

Indelible means not able to be forgotten or removed. Ineffaceable is a synonym meaning unable to be erased.

Incorrigible describes someone or something that cannot be corrected, improved, or reformed. Unreformable is a direct synonym for this state.

Indoctrinate means to teach a person or group to accept a set of beliefs uncritically. Brainwash is a common synonym for this process of forced belief adoption.

Indiscreet refers to lacking good judgment or care in one's behavior or speech. Careless is the closest synonym among the choices.

Infantile describes behavior that is characteristic of an infant or very young child. Immature is the direct synonym for this behavior in older individuals.

Infallible means incapable of making mistakes or being wrong. Sure is the closest synonym in this context, implying certainty or reliability.

Infidelity refers to the action or state of being unfaithful to a spouse or other sexual partner. Adultery is a specific form of infidelity.