IPA: /ˈhɜːrdər/
KK: /ˈhɜrdər/
A person who takes care of and manages a group of animals, usually livestock like cattle or sheep.
The herder guided the sheep across the green pasture.
Herder is formed from "herd" (from Old English "hyrd", meaning a person who tends to a group of animals) and "-er" (meaning a person who). The word "herder" refers to a person who tends to or manages a herd of animals.
Think of someone who takes care of a group of animals — the root 'herd' means a group, and '-er' indicates a person. A herder is someone who manages a herd.