bird vs young lady

bird and young lady both are nouns.

As nouns, young lady is a hypernym of bird; that is, young lady is a word with a broader meaning than bird:

Other hypernyms of bird include miss, missy, girl, fille, young woman.

bird (noun)	young lady (noun)
warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings	a young female
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)	young lady (verb)
watch and study birds in their natural habitat