noun
cold sweat; greasy sweat
Refers to sweat that feels oily or greasy, often associated with nervousness, fear, or illness. The term can describe both the sensation and the appearance of such sweat.
緊張で脂汗が出た。
I broke out in a cold sweat from nervousness.
熱があるとき、脂汗をかくことがある。
When you have a fever, you sometimes break out in a greasy sweat.
Standard kanji spelling; 脂 suggests oily or fatty sweat.
Search-only kanji form; not a standard spelling.
Alternate kanji spelling using 油 (oil); less common than 脂汗.
Rarely used kanji form; 膏 is an uncommon character for oil/fat.
冷や汗 specifically means 'cold sweat' and emphasizes the cool temperature, while 脂汗 focuses on the oily or greasy quality of the sweat, which may or may not be cold.
Compound of 脂 (あぶら, 'oil, fat') and 汗 (あせ, 'sweat'). The exact historical derivation is uncertain, but the word straightforwardly describes sweat that appears oily or greasy.