The baby was dressed in a frilly dress and matching pants

trousers, slacks, breeches, (Oxford) bags, knickerbockers, flannels, shorts, Bermuda shorts or Bermudas, pedal pushers, bell-bottoms, peg-tops, hip-huggers, (blue) jeans, dungarees, denims, Trade Mark Levis, Scots trews; Scots and No. Eng. breeks, US knickers, Colloq cut-offs: Americans who go into British shops asking for a pair of pants are embarrassed to be offered only underwear