Ma'anar ƙamus na kalmar "erythrocyte" wani nau'in tantanin halitta ne a cikin jini wanda ke da alhakin ɗaukar iskar oxygen daga huhu zuwa kyallen takarda da gabobin jiki. Erythrocytes kuma an fi sani da jajayen ƙwayoyin jini saboda suna ɗauke da haemoglobin, furotin da ke ba su launin ja. Wadannan kwayoyin halitta suna samuwa ne a cikin bargon kashi kuma suna daya daga cikin nau'o'in kwayoyin halitta masu yawa a jikin mutum.