below vs under

below is not an adjective while under is an adjective.

Word	Noun	Adjective	Verb	Adverb
below	No	No	No	Yes
under	No	Yes	No	Yes

As adverbs, below and under are synonyms defined as:

below (adjective)	under (adjective)
	located below or beneath something else
	lower in rank, power, or authority

below (adverb)	under (adverb)
(in writing) at a later place	further down
in or to a place that is lower	down below
further down	below the horizon
on a floor below	below some quantity or limit
	in or into a state of subordination or subjugation
	down to defeat, death, or ruin
	into unconsciousness
	through a range downward