續一切經音義 5.251

5.251

烏蒭沙摩（或云烏樞瑟摩梵語輕重也此云穢跡舊云不淨潔金剛俗呼火頭金剛是也）。

烏蒭沙摩 (Or written as 烏樞瑟摩 [Ucchuṣma], reflecting differences in the light or heavy pronunciation of the Sanskrit. Here it is translated as 'Trail of Impurity'; formerly translated as 'Unclean Vajra'; colloquially called 'Fire-Head Vajra').