adjacent vs side by side

adjacent and side by side both are adjectives.

Word	Noun	Adjective	Verb	Adverb
adjacent	No	Yes	No	No
side by side	No	Yes	No	No

As adjectives, adjacent and side by side are synonyms defined as:

adjacent and side by side: nearest in space or position; immediately adjoining without intervening space

Other synonyms of adjacent include next.

adjacent (adjective)	side by side (adjective)
nearest in space or position; immediately adjoining without intervening space	nearest in space or position; immediately adjoining without intervening space
having a common boundary or edge; abutting; touching	closely related or associated
near or close to but not necessarily touching