Unsuitable

Unsuitable is an adjective that describes something not appropriate, fitting, or adequate for a particular purpose or situation. It signals a mismatch between the qualities or conditions of what is being considered and the requirements or expectations of the context. The term can apply to people, objects, plans, or environmental conditions.

In common usage, unsuitable is used to judge whether something should be used or trusted in a given setting. For example, a candidate may be deemed unsuitable for a role, a material unsuitable for high-temperature service, or weather conditions unsuitable for outdoor activities. It is generally neutral, but in some contexts it carries evaluative weight, indicating that alternative options should be sought.

Etymology and related terms: unsuitable is formed by adding the negating prefix un- to suitable. Related terms include suitable, appropriate, fitting, ill-suited, and unfit. In formal writing, synonyms vary in sense: unsuitable emphasizes mismatch with requirements; inappropriate emphasizes social or moral inappropriateness; unfit stresses incapacity or defect.