Late 15c., dews, "the 2 in dice or cards," also "a roll of 2 in dice" (1510s), from Old French deus (Modern French deux), from Latin duos (nominative duo) "two" (from PIE root *dwo- "two"). The spelling -ce from -s to reflect voiceless pronunciation is as in dice, pence, etc.Often used as a nickname for the the second namesake in a family.Trey is the same for number three.
Ex. "drop a deuce" = "defecate"
https://www.urbandictionary.com/define.php?term=Drop%20a%20deuce
https://www.thesaurus.com/e/ways-to-say/synonyms-for-poop/