hacky sack

See also: hackysack and Hacky-Sack

English

Etymology

A trademark of Wham-O. It uses reduplication of the word sack with the word hacky; a "hack", in the game's terminology, is akin to a point, and happens when every player in a group successfully passes the foot bag.

Noun

hacky sack (countable and uncountable, plural hacky sacks)

1. (uncountable, games) A game or activity in which one or a group of players try to keep a footbag off the ground using only the feet.
2. (countable) The foot bag used for such a game.