Sleeve (O. Eng. slieve, or slyf, a word allied to slip, cf. Dutch sloof) is that part of a garment which covers the arm

Arm

In human anatomy, the arm is the part of the upper limb between the shoulder and the elbow joints. In other animals, the term arm can also be used for analogous structures, such as one of the paired forelimbs of a four-legged animal or the arms of cephalopods...

, or through which the arm passes or slips. The pattern of the sleeve is one of the characteristics of fashion in dress, varying in every country and period. Various survivals of the early forms of sleeve are still found in the different types of academic or other robe

Robe

A robe is a loose-fitting outer garment. A robe is distinguished from a cape or cloak by the fact that it usually has sleeves. The English word robe derives from Middle English robe , borrowed from Old French robe , itself taken from the Frankish word *rouba , and is related to the word rob...

s.