The meaning of INAPPROPRIATE is not appropriate : unsuitable. How to use inappropriate in a sentence. INAPPROPRIATE definition: not appropriate; not proper or suitable. See examples of inappropriate used in a sentence. Inappropriate means something that is not suitable or proper in the circumstances. For example, wearing a casual t-shirt to a formal job interview is considered inappropriate because it does not match the expected level of formality. Adjective inappropriate (comparative more inappropriate, superlative most inappropriate) Not appropriate; not suitable for the situation, time, or place. If you say that someone's speech or behaviour in a particular situation is inappropriate, you are criticizing it because you think it is not suitable for that situation. not appropriate; not proper or suitable: an inappropriate dress for the occasion. INAPPROPRIATE definition: 1. unsuitable: 2. unsuitable: 3. unsuitable, esp. for the particular time, place, or situation. Learn more.