16-letter words containing i, n, l, u
- yellow underwing — any of several species of noctuid moths (Noctua and Anarta species), the hind wings of which are yellow with a black bar
- yellowfin (tuna) — a tuna (Thunnus albacares) with yellow fins and a yellow stripe on each side, important as a game and food fish and found worldwide in warm seas
- zollner illusion — a spatial illusion in which parallel lines intersected by short oblique lines are perceived as converging or diverging.