mug

1. A large cup for hot liquids, usually having a handle and used without a saucer.
2. The face, often used deprecatingly.

   What an ugly mug.

3. A gullible or easily-cheated person.

   He's a gullible mug – he believed her again.

4. A stupid or contemptible person.

1. To strike in the face.
2. To assault for the purpose of robbery.
3. To exaggerate a facial expression for communicative emphasis; to make a face, to pose, as for photographs or in a performance, in an exaggerated or affected manner.

   The children weren't interested in sitting still for a serious photo; they mugged for the camera.

4. To photograph for identification; to take a mug shot.
5. To learn or review a subject as much as possible in a short time; cram.

adjective

Easily fooled, gullible.

noun

Motherfucker (usually in similes, e.g. "like a mug" or "as a mug")