Define inappropriate. inappropriate synonyms, inappropriate pronunciation, inappropriate translation, English dictionary definition of inappropriate. adj. Unsuitable or improper. in′ap·pro′pri·ate·ly adv. in′ap·pro′pri·ate·ness n. American Heritage® Dictionary of the English Language, Fifth Edition. Content that includes profanity, personal attacks or antisocial behavior (such as spamming or trolling ), or other inappropriate content or material will be removed. Synonyms for INAPPROPRIATE: unsuitable, improper, incorrect, wrong, unhappy, unfit, irrelevant, unfortunate; Antonyms of INAPPROPRIATE: appropriate, suitable, correct, proper, right, relevant, happy, fitting INAPPROPRIATE definition: 1. unsuitable: 2. unsuitable: 3. unsuitable, esp. for the particular time, place, or situation. Learn more. The meaning of INAPPROPRIATE is not appropriate : unsuitable. How to use inappropriate in a sentence. Inappropriate refers to something that is not suitable or proper in the circumstances. It denotes behavior, language, action, or expression that is out of place, offensive, or violates certain social norms, standards, or rules of a given context. The word appropriate means correct or proper and since the little prefix in turns its meaning around, something inappropriate is considered not proper or suitable. Something that is inappropriate is not useful or suitable for a particular situation or purpose. The industry is inappropriate to the region's present and future needs. There is no suggestion that clients have been sold inappropriate policies. Adjective inappropriate (comparative more inappropriate, superlative most inappropriate) Not appropriate; not suitable for the situation, time, or place. INAPPROPRIATE definition: not appropriate; not proper or suitable. See examples of inappropriate used in a sentence.