earhat
A band, often made of a knitted material, that covers the ears but not the top of one's head, therefore not a hat-hat...just an ear hat. Similar to a wide sweat band, but it isn't. Not ear muffs...those are ear muffs. It's really self explanatory...not sure why you had to look this up....
My ears are cold, but I hate hats, therefore I shall wear my earhat.