Sleeve

n. [A-S. slēf, slūf, slēfe, slūfe, from slēfan, slūfan, to put on, to clothe; O. H. Ger. slauf, slouph, M. H. Ger. slouf, Prov. Ger. schlauf, clothing.]

1. The part of a garment that is fitted to cover the arm; as, the sleeve of a coat or gown.
2. A knot or snarl in silk or other thread;—the same as SLEAVE, q. v.
3. A narrow channel of water. [Rare.] “The Celtic Sea, called oftentimes the Sleeve.” Drayton.
4. (Mach.) (a.) A tubular part, resembling in form or position the sleeve of a coat, to cover, sustain, or steady another part that moves within it. (b.) A long bushing or thimble, as in the nave of a wheel.

To laugh in the sleeve, to laugh privately or unperceived, especially while apparently preserving a grave or serious demeanor toward the person or persons laughed at; that is, perhaps, originally, by hiding the face in the wide sleeves of former times.—To pin or hang on the sleeve of, to be or make dependent upon.