bird vs birder birder vs bird

bird and birder both are nouns.

bird is a verb but birder is not a verb.

bird (noun) birder (noun)
warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings a person who identifies and studies birds in their natural habitats
the flesh of a bird or fowl (wild or domestic) used as food
informal terms for a (young) woman
a cry or noise made to express displeasure or contempt
badminton equipment consisting of a ball of cork or rubber with a crown of feathers
bird (verb) birder (verb)
watch and study birds in their natural habitat