also: きすいせん
noun
jonquil
A species of Narcissus with fragrant yellow flowers; often written in katakana as キズイセン.
庭にキズイセンが咲いている。
Jonquils are blooming in the garden.
水仙 is the general term for daffodil/narcissus; 黄水仙 specifically refers to the jonquil species (Narcissus jonquilla).
From 黄 (yellow) + 水仙 (daffodil), referring to the yellow-flowered jonquil.