cub vs tiger cub

cub and tiger cub both are nouns.

Word	Noun	Adjective	Verb	Adverb
cub	Yes	No	Yes	No
tiger cub	Yes	No	No	No

As nouns, tiger cub is a hyponym of cub; that is, tiger cub is a word with a more specific, narrower meaning than cub:

cub: the young of certain carnivorous mammals such as the bear or wolf or lion
tiger cub: a young tiger

Other hyponyms of cub include lion cub, bear cub.

cub (noun)	tiger cub (noun)
the young of certain carnivorous mammals such as the bear or wolf or lion	a young tiger
a male child (a familiar term of address to a boy)
an awkward and inexperienced youth

cub (verb)	tiger cub (verb)
give birth to cubs