burn down vs burn up

burn down and burn up both are verbs.

Word	Noun	Adjective	Verb	Adverb
burn down	No	No	Yes	No
burn up	No	No	Yes	No

As verbs, burn down and burn up are synonyms defined as:

burn down and burn up: burn completely; be consumed or destroyed by fire

Other synonyms of burn down include go up.

burn down (verb)	burn up (verb)
burn completely; be consumed or destroyed by fire	burn completely; be consumed or destroyed by fire
destroy by fire	use up (energy)
	burn brightly