be (as) thick as thieves

US /bi əz θɪk əz θiːvz/
UK /bi əz θɪk əz θiːvz/
"be (as) thick as thieves" picture
1.

çok yakın arkadaş, sırdaş

to be very close friends and share secrets, often in a way that excludes others

:
Those two have been as thick as thieves since childhood.
O ikisi çocukluktan beri çok yakın arkadaş.
The new neighbors are already as thick as thieves with the family next door.
Yeni komşular, yan komşu aileyle şimdiden çok yakın arkadaş oldular.