n (computing) (plural 'mice' or, rarely, 'mouses') An input device that is moved over a pad or other flat surface to produce a corresponding movement of a pointer on a graphical display.
n (nautical) A turn or lashing of spun yarn or small stuff, or a metallic clasp or fastening, uniting the point and shank of a hook to prevent its unhooking or straighening out.
v (intransitive) To move cautiously or furtively, in the manner of a mouse (the rodent) (frequently used in the phrasal verb 'to mouse around').