1com·ple·ment 
/ˈkɑ:mpləmənt/ noun
plural com·ple·ments /ˈkɑ:mpləmənt/ noun [count] 1 : something that completes something else or makes it better
▪ The scarf is a perfect complement to her outfit. 2 : the usual number or quantity of something that is needed or used
▪ a full complement of farm animals ▪ her usual complement of attendants ▪ a ship's complement of officers 3 grammar : a word or group of words added to a sentence to make it complete
▪ “President” in “they elected her president” and “to work” in “he wants to work” are different kinds of complements.
▪ The scarf is a perfect complement to her outfit.
▪ a full complement of farm animals ▪ her usual complement of attendants ▪ a ship's complement of officers
▪ “President” in “they elected her president” and “to work” in “he wants to work” are different kinds of complements.
Do not confuse complement with compliment.
