pear vs pear tree

pear and pear tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
pear	Yes	No	No	No
pear tree	Yes	No	No	No

As nouns, pear and pear tree are synonyms defined as:

pear and pear tree: Old World tree having sweet gritty-textured juicy fruit; widely cultivated in many varieties

Other synonyms of pear include Pyrus communis.

pear (noun)	pear tree (noun)
sweet juicy gritty-textured fruit available in many varieties	Old World tree having sweet gritty-textured juicy fruit; widely cultivated in many varieties
Old World tree having sweet gritty-textured juicy fruit; widely cultivated in many varieties