1. bongcloud - Noun
2. bongcloud - Verb
bongcloud (plural bongclouds)
A chess opening in which white's king is advanced to the second rank on the second move, for example, 1.e4 e5 2.Ke2, thus preventing white from being able to castle and allowing black to develop with tempo.
(intransitive) To play such an opening.
(intransitive) To advance one's king to the second rank without first castling.
Source: en.wiktionary.org