发小

髮小
fàxiǎo
  1. (dialect) close childhood friend whom one grew up with
  2. a couple who grew up as childhood friends

CEDICT

dialect

Entry Composition

1 发 fà
  1. hair
  2. Taiwan pr. fǎ
2 小 xiǎo
  1. small
  2. tiny
  3. few
  4. young