puppy fat vs adipose tissue

puppy fat and adipose tissue both are nouns.

Word	Noun	Adjective	Verb	Adverb
puppy fat	Yes	No	No	No
adipose tissue	Yes	No	No	No

As nouns, adipose tissue is a hypernym of puppy fat; that is, adipose tissue is a word with a broader meaning than puppy fat:

puppy fat: fat on the body of a baby or child; disappears at adolescence
adipose tissue: a kind of body tissue containing stored fat that serves as a source of energy; it also cushions and insulates vital organs

Other hypernyms of puppy fat include fat, fatty tissue.

puppy fat (noun)	adipose tissue (noun)
fat on the body of a baby or child; disappears at adolescence	a kind of body tissue containing stored fat that serves as a source of energy; it also cushions and insulates vital organs