(1):

(n.) One who, or that which, sticks; as, a bill sticker.

(2):

(n.) That which causes one to stick; that which puzzles or poses.

(3):

(n.) In the organ, a small wooden rod which connects (in part) a key and a pallet, so as to communicate motion by pushing.

(4):

(n.) Same as Paster, 2.