IPA: /ˈhɛərˌbænd/
KK: /hɛrˌbænd/
A band or elastic material worn around the head to hold hair back or in place.
She wore a colorful hairband to keep her hair out of her face while running.
Hairband → The word is formed from "hair" (from Old English *haer*, meaning the fine strands growing from the skin of humans and animals) and "band" (from Old English *banda*, meaning a strip or ribbon). A hairband is a strip or ribbon used to hold hair together.
Think of a 'strip' ('band') used to hold 'hair' in place — that's what a hairband does.