lukewarm

Lukewarm describes a temperature that is moderately warm, neither hot nor cold. In everyday use, it refers to substances and environments that feel pleasantly warm to the touch but not hot, such as lukewarm water or tea that has cooled from its initial temperature.

Originating in Middle English, the term combines a form of luked meaning tepid with warm to distinguish tepid warmth from heat. It has long been used to describe physical warmth as well as attitudes or responses that are not enthusiastic.

Exact ranges vary by context, but lukewarm commonly refers to roughly 20 to 40°C (68 to 104°F). In culinary or beverage contexts, it often implies around 30 to 40°C, a temperature comfortable to touch but not hot.

Metaphorically, lukewarm denotes a lack of enthusiasm or conviction, as in a lukewarm reception or a lukewarm response. In religious or moral discourse, it can signal indifference or complacency toward zeal or conviction.

Related terms include tepid and lukewarmness, which are used to describe similar ideas of moderate warmth or a tepid level of interest.