Ma'anar ƙamus na kalmar "harbin baya" yana nufin nau'in harbi a wasanni na raket, kamar wasan tennis ko badminton, inda mai kunnawa ya buga kwallon da bayan hannunsu yana fuskantar alkiblar harbi. Ana amfani da tuƙi na baya don buga ƙwallon da ke gefe na jikin ɗan wasan daga hannun raket ɗin su. Motar baya shine bugun jini na yau da kullun da ake amfani dashi a cikin matches guda ɗaya da biyu, kuma fasaha ce mai mahimmanci ga kowane ɗan wasa da ke neman haɓaka wasansa.