1 scowl, glower, glare, knit one's brows, grimace, give a dirty look, Brit lour or lower, US lower:
Don't frown so much or you'll get wrinkles.
2 frown on or upon. disapprove (of), (look on or regard or view with) disfavour, discountenance, look down on or upon, look askance at, not take kindly to, not think much of, look disapprovingly upon, Colloq take a dim view of, be turned off by:
My parents frown on my seeing you.
3 scowl, glower, glare, grimace, dirty look, Brit lour or lower, US lower:
Her forehead is always furrowed by a frown.