(playing cards) A playing card that is the only one of its suit in a hand, especially at bridge. / (playing cards) A hand containing only one card of a certain suit.

(anatomy, zootomy) A pouch or cavity in a bone or other tissue, especially one in the bones of the face or skull connecting with the nasal cavities (the paranasal sinus).

(pathology) An inflammation of one or more paranasal sinuses.

One who sinks something. / (fishing) A weight used in fishing to cause the line or net to sink.

(baseball) The motion of a sharply diving sinker pitch.

The unified currency proposed for all EU states; it became the Euro.

present participle of sink

The process by which something sinks, or is sunk.

The quality or state of being sincere

Tough; having strong sinews. / (figuratively) Having or showing nervous strength. / (of a person or animal) Possessing physical strength and weight; rugged and powerful.