A "knit beanie" refers to a type of hat that is made by knitting threads or yarns together. It is a warm and snug head covering usually worn in colder weather. Full definition
Twisted knit beanie with faux fur Pom Pom. (ilymix.com)
Today I'm wearing this jumper dress, with black leggings, quilted vegan leather boots, a simple black knitted beanie hat, and a long blue scarf. (onlinepersonalstylist.com)
I love a good chunky knit beanie for winter! (hellorigby.com)