lopper vs pruning saw

lopper and pruning saw both are nouns.

Word	Noun	Adjective	Verb	Adverb
lopper	Yes	No	No	No
pruning saw	Yes	No	No	No

As nouns, pruning saw is a hypernym of lopper; that is, pruning saw is a word with a broader meaning than lopper:

lopper: a long-handled pruning saw with a curved blade at the end and sometimes a clipper; used to prune small trees
pruning saw: a handsaw used for pruning trees

lopper (noun)	pruning saw (noun)
a long-handled pruning saw with a curved blade at the end and sometimes a clipper; used to prune small trees	a handsaw used for pruning trees