一義，有形之物質。一義，無形之空界。俱舍論界品曰：「阿伽謂積集色，極能為礙，故名阿伽。有說，阿伽即空界色，此中無礙，故名阿伽。」玄應音義二十四曰：「阿伽色。伽，此云礙。阿有二義，或言無，或云極。猶含兩釋，故立本名也。」俱舍寶疏一下曰：「阿伽是極礙也，又阿伽為無礙梵語阿伽，通此二義。」梵Aghaṁ。
agna, but may beākāśa; it has two opposite interpretations, substantial and unsubstantial, the latter having special reference to the empyrean.