A left-hander is someone who uses the left hand for the skilled jobs: writing, throwing, holding a racket, and so on. About one person in ten is like this. The adjective is left-handed (she is left-handed); the noun for the person is left-hander (she is a left-hander). It is a calm, everyday word — not a joke and not a medical label. Tools, scissors, and school desks are often made for the right hand, so left-handers notice that the world is slightly built the other way. In sport, commentators use it a lot, especially for pitchers and bowlers, because a left-hander’s throw comes from a side the other player sees less often.