1) Ass 1) Donkey, at times 2) Donkey, frequently 3) Donkey, sound-wise 4) Ink roller 
A brayer is a hand roller used in printmaking techniques to spread ink in the process of offsetting an image from a plate to paper. ==Materials== They can be made of composition rubber, rubber, sponge, acrylic, polyurethane or leather. They are mounted on a rod or pins, attached to a wooden handle somewhat shaped to accommodate the hand. Others ha...
instrument for spreading ink in printing
• (n.) One that brays like an ass. • (n.) An implement for braying and spreading ink in hand printing.
rubber stamp tool that has a rubber wheel on a handle used to make backgrounds and other techniques. it is like a paint roller with rubber. There are many techniques possible with brayers.
Bray'er noun An implement for braying and spreading ink in hand printing. 
a small roller for inking type by hand, usually for making a proof.