Stackable Mugs

stackable
(stackability) The quality of being stackable
(stack-ability) Where a connector has its length and/or breadth narrow enough to allow two connectors to be placed together, and maintain contact pitch centres. This can be side-to-side (side stackable) or end-to-end (end stackable).
(Stackability) To "stack" means that the player can run one play mode while another mode is in progress. This strategy usually yields higher scores. A noted example of this is Williams' Bram Stoker's Dracula, with its Multi-Multiball feature.

mugs
A large cup, typically cylindrical and with a handle and used without a saucer
A person's face
(mug) the quantity that can be held in a mug
(mug) rob at gunpoint or with the threat of violence; "I was mugged in the streets of New York last night"
The contents of such a cup
(mug) chump: a person who is gullible and easy to take advantage of