jolly vs pretty

jolly is a noun but pretty is not a noun.

Word	Noun	Adjective	Verb	Adverb
jolly	Yes	Yes	Yes	Yes
pretty	No	Yes	No	Yes

As adverbs, jolly and pretty are synonyms defined as:

Other synonyms of jolly include fairly, middling, moderately, passably, reasonably, somewhat.

jolly (noun)	pretty (noun)
a yawl used by a ship's sailors for general work
a happy party

jolly (adjective)	pretty (adjective)
full of or showing high-spirited merriment	(used ironically) unexpectedly bad
	pleasing by delicacy or grace; not imposing

jolly (verb)	pretty (verb)
be silly or tease one another

jolly (adverb)	pretty (adverb)
to certain extent or degree	to certain extent or degree