Steaming means giving off hot vapour. A steaming mug, steaming horses, steaming hot.
The vapour you actually see is condensed droplets, since steam itself is invisible, but the word describes what a cold morning does to anything warm. In British slang, steaming also means very drunk, and steaming mad means furious.
1adjectivesteamingGiving off hot vapour.
“She handed me a steaming bowl of soup.”
steaming is a quality.
Proto-Indo-European
*dʰewh₂- — to whirl, waft, stink, shake; steam, haze, smoke
Proto-Germanic
*staumaz — steam, vapour, breath
Old English
stēam — steam, hot exhalation, hot breath; that which emits vapour; blood
Middle English
steem
English
steam
English, today
steaming
by surface analysis, steam + -ing. steam comes from Middle English steem, stem, from Old English stēam (“steam, hot exhalation, hot breath; that which emits vapour; blood”), from Proto-Germanic staumaz (“steam, vapour, breath”), from Proto-Indo-European dʰewh₂- (“to whirl, waft, stink, shake; steam, haze, smoke”). Cognate with Scots stem, steam (“steam”), West Frisian steam (“steam, vapour”), Dutch stoom (“steam, vapour”), Low German stom (“steam”), Swedish - dialectal stimma (“steam, fog”), Latin fūmus (“smoke, steam”).
Etymology from Wiktionary, CC BY-SA