Meaning

noun the cardinal number that is the sum of nine and one; the base of the decimal system

noun the 24th letter of the Roman alphabet

noun street names for methylenedioxymethamphetamine

originFrom Christ by abbreviation, orthographic borrowing from Ancient Greek Χ (Kh, letter chi), from Χριστός (Khristós, “Christ”).

Etymology from Wiktionary, CC BY-SA 3.0