objection vs complaint

objection and complaint both are nouns.

Word	Noun	Adjective	Verb	Adverb
objection	Yes	No	No	No
complaint	Yes	No	No	No

As nouns, complaint is a hyponym of objection; that is, complaint is a word with a more specific, narrower meaning than objection:

objection (noun)	complaint (noun)
(law) a procedure whereby a party to a suit says that a particular line of questioning or a particular witness or a piece of evidence or other matter is improper and should not be continued and asks the court to rule on its impropriety or illegality	an expression of grievance or resentment
the act of protesting; a public (often organized) manifestation of dissent	(formerly) a loud cry (or repeated cries) of pain or rage or sorrow
the speech act of objecting	(civil law) the first pleading of the plaintiff setting out the facts on which the claim for relief is based
the act of expressing earnest opposition or protest	(criminal law) a pleading describing some wrong or offense
	an often persistent bodily disorder or disease; a cause for complaining