Meaning of bidie-in in English:

bidie-in

Pronunciation /ˌbʌɪdɪˈɪn/

noun

(also bidey-in)
informal Scottish
  • A person who lives with his or her partner in a non-marital relationship; a cohabiting partner.

Origin

Early 20th century; earliest use found in James Milne (b. 1865). From bide + -y + in.