tree hugger vs conservationist

tree hugger and conservationist both are nouns.

Word	Noun	Adjective	Verb	Adverb
tree hugger	Yes	No	No	No
conservationist	Yes	No	No	No

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

tree hugger: derogatory term for environmentalists who support restrictions on the logging industry and the preservation of forests
conservationist: someone who works to protect the environment from destruction or pollution

Other hypernyms of tree hugger include environmentalist.

tree hugger (noun)	conservationist (noun)
derogatory term for environmentalists who support restrictions on the logging industry and the preservation of forests	someone who works to protect the environment from destruction or pollution