biased vs one-sided

biased and one-sided both are adjectives.

Word	Noun	Adjective	Verb	Adverb
biased	No	Yes	No	No
one-sided	No	Yes	No	No

As adjectives, biased and one-sided are synonyms defined as:

Other synonyms of biased include colored, coloured, slanted.

biased (adjective)	one-sided (adjective)
favoring one person or side over another	not reversible or capable of having either side out
	involving only one part or side
	favoring one person or side over another