Rare term for shark fin as a food ingredient; the more common word is 鱶鰭 (ふかひれ).
See also: フカヒレ
Shark fin is sometimes treated as a luxury ingredient.
Compound of 鱶 (ふか, 'shark') and 潤目 (うるめ, possibly referring to a type of fish or a preparation method). The exact derivation is uncertain.