knit (one's) brow

Translations
нахмурить брови
She knit her brow in concentration as she tried to solve the puzzle.
Она нахмурила брови в концентрации, пытаясь решить головоломку.
Definitions
To furrow or wrinkle one's forehead, typically as a sign of concentration, worry, or disapproval.
Words
brow

noun
бровь
knit

verb
вязать