triple run; three color straight
A mahjong hand containing the same numerical sequence (chow) in all three suits. Often worth 2 han when the hand is closed.
Sanshoku doujun is a yaku where you form the same sequence in the man, pin, and sou suits.
If the hand is closed, sanshoku doujun is worth two han.
三色同刻 is a triple triplet (same number in all three suits), while 三色同順 is a triple sequence.
一気通貫 is a straight of 1–9 in one suit, whereas 三色同順 requires the same sequence across all three suits.
From 三色 (three colors/suits) + 同順 (same sequence). A standard mahjong term.