warm ‧ er /ˈwɔːmə $ ˈwɔːrmər/ BrE AmE noun [countable]
[ Word Family: noun : ↑ warmth , the warm, ↑ warmer , ↑ warming ; adverb : ↑ warmly , ↑ warm ; adjective : ↑ warm , ↑ warming ; verb : ↑ warm ]
something, especially a piece of equipment, that is used to make or keep things warm:
a plate warmer