trans ‧ form ‧ er /trænsˈfɔːmə $ -ˈfɔːrmər/ BrE AmE noun [countable]
[ Word Family: noun : ↑ form , ↑ formation , ↑ transformation , ↑ reformer , ↑ reform , ↑ reformation , ↑ reformist , ↑ transformer , ↑ formlessness ; verb : ↑ form , ↑ reform , ↑ transform ; adjective : reformed, ↑ reformist , ↑ formless ; adverb : ↑ formlessly ]
a piece of equipment for changing electricity from one ↑ voltage to another