big six

Short definition from Wiktionary

Noun

1. 1
   In the game of craps, a prominent space on the table where one can place a bet that the shooter will roll a six before a seven.

Proper noun

1. 1
   The six elements most used by life: carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.
2. 2
   The six English obscenities: "cunt", "fuck", "cock", "arse/ass", "shit", and "piss".