Ma'anar ƙamus na kalmar "a gefen" sifa ce da ke bayyana ɗan wasa ko ƙungiyar da ke cikin wasan motsa jiki wanda ke cikin matsayi na doka ko karɓuwa bisa ga ƙa'idodin wasan. Musamman, a cikin wasanni kamar ƙwallon ƙafa (ƙwallon ƙafa), rugby, da ƙwallon ƙafa na Amurka, an ce ɗan wasa yana waje idan suna cikin rabin filin su ko kuma idan sun yi daidai da ƙwallon ko kuma mai tsaron gida na biyu zuwa na ƙarshe. 'yan wasan da ke hamayya a lokacin da aka ba su kwallon. Gabaɗaya, kasancewa a gefe yana nufin kasancewa a matsayin da zai ba ɗan wasan damar shiga wasan cikin gaskiya da adalci, ba tare da keta doka ko ƙa'ida ba.