shady vs suspicious

shady and suspicious both are adjectives.

Word	Noun	Adjective	Verb	Adverb
shady	No	Yes	No	No
suspicious	No	Yes	No	No

As adjectives, shady and suspicious are synonyms defined as:

Other synonyms of shady include fishy, funny, suspect.

shady (adjective)	suspicious (adjective)
quiet, dark, or concealed	openly distrustful and unwilling to confide
of questionable honesty or legality	not as expected
not as expected
filled with shade