Tepid means only slightly warm, like bathwater that's lost its heat or tea that's been sitting out too long. When you test the temperature of something tepid with your finger, it feels neither hot nor cold, just disappointingly lukewarm.

The word also describes enthusiasm that's weak or halfhearted. When your friend gives a tepid response to your exciting news about making the soccer team, saying just “oh, that's nice” without much energy, you can tell they're not really interested. Tepid applause means people are clapping politely but without real excitement. A tepid review of a new movie suggests the critic found it merely okay, nothing special.

Think of tepid as the temperature version of “meh.” A tepid swimming pool on a hot day won't refresh you. A tepid welcome in a new classroom won't make you feel particularly wanted. Whether it's describing actual temperature or someone's level of interest, tepid suggests something that's present but lacking any real warmth or energy.