Kalmar “allyl radical” tana nufin wani nau’in sinadari da ke dauke da na’urar lantarki da ba a hade ba kuma ana samuwa ne ta hanyar cire sinadarin hydrogen atom daga kungiyar allyl, wato sarkar carbon guda uku mai hade biyu a tsakiya da kuma guda bond a kan kowane karshen. Matsakaicin allyl yana da matuƙar amsawa kuma yana shiga cikin halayen sinadarai iri-iri, gami da polymerization, ƙari, da halayen maye. Tsarin sinadaransa shine C3H5•, inda ɗigon ke nuna kasancewar na'urar lantarki mara ɗabi'a.