mi·cro·therm \ˈmīkrəˌthərm\noun Etymology: International Scientific Vocabulary micr- + -therm : a plant requiring a mean annual temperature between 0° and 14° C for full growth — compare megatherm, mesotherm • mi·cro·ther·mic\| ̷ ̷ ̷ ̷|thərmik\adjective