pin oak vs oak tree

pin oak and oak tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
pin oak	Yes	No	No	No
oak tree	Yes	No	No	No

As nouns, oak tree is a hypernym of pin oak; that is, oak tree is a word with a broader meaning than pin oak:

pin oak: fast-growing medium to large pyramidal deciduous tree of northeastern United States and southeastern Canada having deeply pinnatifid leaves that turn bright red in autumn; thrives in damp soil
oak tree: a deciduous tree of the genus Quercus; has acorns and lobed leaves

Other hypernyms of pin oak include oak.

As nouns, oak tree is a hypernym of pin oak; that is, oak tree is a word with a broader meaning than pin oak:

pin oak: large nearly semi-evergreen oak of southeastern United States; thrives in damp soil
oak tree: a deciduous tree of the genus Quercus; has acorns and lobed leaves

Other hypernyms of pin oak include oak.

pin oak (noun)	oak tree (noun)
fast-growing medium to large pyramidal deciduous tree of northeastern United States and southeastern Canada having deeply pinnatifid leaves that turn bright red in autumn; thrives in damp soil	a deciduous tree of the genus Quercus; has acorns and lobed leaves
large nearly semi-evergreen oak of southeastern United States; thrives in damp soil