Gileishiya ( US : / ɡ l eɪ ʃ ər / ko UK : / ɡ l æ s i ər, Ɡ l eɪ s i ər / ) ne m jikin m kankara cewa ne kullum motsi ƙarƙashin da kansa nauyi. Dusar ƙanƙara ta kan fito inda tarin dusar ƙanƙara ta wuce zubar da ciki a cikin shekaru da yawa, galibi ƙarnuka. Gileshiya sannu a hankali suna lalacewa kuma suna gudana ƙarƙashin matsin lamba wanda nauyin su ya haifar, suna ƙirƙirar crevasses, seracs, da sauran fasali masu rarrabewa. Suna kuma lalata dutsen da tarkace daga matattarar su don ƙirƙirar tsarin ƙasa kamar cirques, moraines, ko fjords. Gileshiya suna samuwa ne kawai a ƙasa kuma sun bambanta da kankara mai ƙanƙantar da kankara da ƙanƙarar tafkin da ke samuwa a saman ruwa. Kaso 99% na duniya ya kunshi tsaunukan kankarar na gileshiya wanda ya zarce har a cikin sararin kankara zanen gado (wanda kuma aka sani da suna "nahiyar gileshiya") a cikin iyakacin duniya yankuna, amma glaciers za a iya samu a dutsen jeri a kan kowane nahiyar wasu fiye da Australian ɓangaren duniya ciki har da Oceania ta high-latitud Oceanic tsibirin kasashe irin su New Zealand.