马甲线

馬甲線
mǎjiǎxiàn
(neologism c. 2013) (coll.) vertical groove visible on either side of the belly in a person with well-toned abs

CEDICT

neologism colloquial

Entry Composition

1 马甲 mǎjiǎ
  1. corset
  2. sockpuppet (Internet slang)
  3. vest (dialect)
=2 线 xiàn variant of 线 xiàn
=2 线 xiàn
  1. thread
  2. string
  3. wire
  4. line
  5. (after a number) tier (unofficial ranking of a Chinese city)

classifiers: 條, 股, 根