warm
v.v. to make something a little bit hot, or to become hotter yourself. You often use this when you are getting ready for exercise or heating up food.
v. to increase the temperature of an object or environment slightly; to prepare for physical exertion by performing light movements. Often used with the particle 'up' to indicate a process of reaching a desired temperature.
I need to warm my hands by the fire.
The athletes began to warm up on the track twenty minutes before the race started.
As the sun began to rise, the morning air started to warm, gradually melting the thin layer of frost that had settled on the valley floor overnight.
From Middle English warm, werm, from Old English wearm, from Proto-West Germanic warm, from Proto-Germanic warmaz, either from Proto-Indo-European wór-mo-s, from wer- (“to burn”), or Proto-Indo-European gʷʰor-mo-s, from the root gʷʰer- (“warm, hot”). Cognate with West Frisian waarm, Saterland Frisian woorm, Dutch warm, German warm, Swedish varm, Icelandic varmur, Ancient Greek θερμός (thermós) (in which case perhaps a distant doublet of thermos), Latin formus, Sanskrit घर्म (gharmá), or alternatively from Proto-Indo-European *wer- (“to burn”), related to Hittite 𒉿𒊏𒀀𒉌 (warāni, “to burn”), Armenian վառել (vaṙel, “to burn, heat, warm”), Old Church Slavonic варити (variti, “to cook, boil”).
From Middle English warmen, wermen, wyrmen, from Old English wierman (“to make warm”) and wearmian (“to become warm”), from Proto-West Germanic warmijan and warmōn. Cognate with Dutch warmen, German wärmen, Swedish värma.
Often functions as a phrasal verb ('warm up'). When used transitively, it requires a direct object such as food, a room, or a part of the body.
I am warming for the gameI am warming up for the gameWhen referring to preparing for exercise, the phrasal verb 'warm up' is required; 'warm' alone usually refers to physical temperature.