Meaning:
“截” means “to cut,” and “胡,” a term used in the game of mahjong, means “winning by claiming the tile that another player has discarded. When more than one person in a game can claim a discarded tile to win, only the one who sits counterclockwise right next to the person who discards the tile is recognized as the winner. The term “截胡” describes this scenario where one person beats others with this sequential priority in a mahjong game. Chinese netizens also use the term to describe the scenarios where one person claims another’s trophy when the other person is close to success, or one person wins the heart of a member of the opposite sex who has been dating another.
Example:
A: 怎么最近没见到小林的漂亮女朋友？
Zěnme zuìjìn méi jiàndào xiǎolín de piàoliang nǚpéngyou？
Why hasn’t Xiao Lin’s pretty girlfriend been around lately?
B: 你可别当着他的面提这茬儿。他的女朋友被一个富二代截胡了。
Nǐ kě bié dāngzhe tāde miàn tí zhè chár。Tā de nǚpéngyou bèi yīgè fù’èrdài jiéhú le。
You’d better not talk about it when Xiao Lin’s here. Her heart was stolen by a dude who was born loaded.