pile-on

n.

An activity involving several individuals jumping (or piling) on top of an unfortunate victim, forming a pile of people. This person then becomes the target of the pile-on.

Pile-ons are often deliberately instigated as pranks.

This is normally triggered by someone mentioning the words "pile on", or a word phonetically similar, e.g. "pylon".

Synonyms:

stacks-on (Australia), bundle, monkey pile, pig pile, or dog pile.

pen spinning

n.

A recreational activity of using one's fingers to manipulate a pen in aesthetically pleasing ways.

This is done through the combination of various tricks.

sport stacking

n.

Formerly known as cup stacking.

An individual and team activity / game played using plastic cups.

Participants of sport stacking stack and unstack cups in pre-determined sequences, competing against the clock or another player. Sequences are usually pyramids of three, six or ten upside-down cups.