scrimmage vest
noun [ C ] US uk/ˈskrɪm.ɪdʒ ˌvest/ us/ˈskrɪm.ɪdʒ ˌvest/ (also practice pinny, /ˈpræk.tɪs ˌpɪn.i/ /ˈpræk.tɪs ˌpɪn.i/); (UK bib)
（体育比赛中所穿的）背心
a piece of clothing like a light shirt with no sleeves that is worn over other clothing, for example in team games, to show which team a person is playing for