i Register
In some senses, frowny is marked as informal. Watch for register when choosing this word.
adj
Frowning.
She made a frowny face.
[…] the black-and-white splendor of our men, as well as the fur-decked rosiness of our women, is only enhanced by contrast against the frowny murkings of the sky.
noun
Ellipsis of frowny face.