sideways vs obliquely

sideways is an adjective but obliquely is not an adjective.

Word	Noun	Adjective	Verb	Adverb
sideways	No	Yes	No	Yes
obliquely	No	No	No	Yes

As adverbs, sideways and obliquely are synonyms defined as:

Other synonyms of sideways include sidelong.

sideways (adjective)	obliquely (adjective)
(of movement) at an angle

sideways (adverb)	obliquely (adverb)
to, toward or at one side	at an oblique angle
from the side; obliquely	to, toward or at one side
with one side forward or to the front
in a lateral direction