complement

noun

1. (countable, uncountable)The totality, the full amount or number which completes something.

   “Queequeg sought a passage to Christian lands. But the ship, having her full complement of seamen, spurned his suit; and not all the King his father's influence could prevail.”

   “Some 11 members of Somerton council's complement of 15 stepped down on Tuesday.”

2. (countable, uncountable)The whole working force of a vessel.
3. (countable, uncountable)An angle which, together with a given angle, makes a right angle.
4. (countable, uncountable)Something which completes, something which combines with something else to make up a complete whole; loosely, something perceived to be a harmonious or desirable partner or addition.

   “History is the complement of poetry.”

   “It would be too much to imagine that improving stations will alone create a much needed new image in the public eye; a smartly turned out station staff is a very necessary complement to a smart station.”

   “London's Kings Place, now one year old, established itself as a venue for imaginative programming, a complement to the evergreen Wigmore Hall.”

5. (countable, uncountable)A word or group of words that completes a grammatical construction in the predicate and that describes or is identified with the subject or object.

   “Why has our grammar broken down at this point? It is not difficult to see why. For, we have failed to make any provision for the fact that only some Verbs in English (i.e. Verbs like those italicized in (5) (a), traditionally called Transitive Verbs) subcategorize ( = ‘takeʼ) an immediately following NP Complement, whereas others (such as those italicised in (5) (b), traditionally referred to as Intransitive Verbs) do not.”

6. (countable, uncountable)A phonetic complement is a graphic element that modifies another, such as (in Linear B script) a small syllabogram that is attached to a logogram as an abbreviation of its reading (as opposed to an adjunct that abbreviates an adjective that modifies that logogram).
7. (countable, uncountable)An interval which, together with the given interval, makes an octave.
8. (countable, uncountable)The color which, when mixed with the given color, gives black (for mixing pigments) or white (for mixing light).

   “The complement of blue is orange.”

9. (countable, uncountable)Given two sets, the set containing one set's elements that are not members of the other set (whether a relative complement or an absolute complement).

   “The complement of the odd numbers is the even numbers, relative to the natural numbers.”

10. (countable, uncountable)One of several blood proteins that work with antibodies during an immune response.
11. (countable, uncountable)An expression related to some other expression such that it is true under the same conditions that make other false, and vice versa.
12. (countable, uncountable)A voltage level with the opposite logical sense to the given one.
13. (countable, uncountable)A bit with the opposite value to the given one; the logical complement of a number.
14. (countable, uncountable)The diminished radix complement of a number; the nines' complement of a decimal number; the ones' complement of a binary number.

    “The complement of 01100101#95;2 is 10011010#95;2.”

15. (countable, uncountable)The radix complement of a number; the two's complement of a binary number.

    “The complement of 01100101#95;2 is 10011011#95;2.”

16. (countable, uncountable)The numeric complement of a number.

    “The complement of −123 is 123.”

17. (countable, uncountable)A nucleotide sequence in which each base is replaced by the complementary base of the given sequence: adenine (A) by thymine (T) or uracil (U), cytosine (C) by guanine (G), and vice versa.

    “A DNA molecule is formed from two strands, each of which is the complement of the other.”

18. (countable, uncountable)Synonym of alexin.
19. (abbreviation, alt-of, countable, uncountable)Abbreviation of complementary good.
20. (archaic, countable, uncountable)Something (or someone) that completes; the consummation.

    “perform all those works of mercy, which Clemens Alexandrinus calls amoris et amicitiæ impletionem et extentionem, the extent and complement of love[…].”

21. (countable, obsolete, uncountable)The act of completing something, or the fact of being complete; completion, completeness, fulfilment.

    “And both encreast the prayse of woman kynde, / And both encreast her beautie excellent: / So all did make in her a perfect complement.”

22. (countable, obsolete, uncountable)Something which completes one's equipment, dress etc.; an accessory.

    “A doleful case desires a doleful song, Without vain art or curious complements.”

    “Garnish'd and deck'd in modest complement,”

    “A man should be judged by himselfe, and not by his complements.”

23. (countable, uncountable)Obsolete spelling or misspelling of compliment.

    “A man of complements”

verb

1. To complete, to bring to perfection, to make whole.

   “We believe your addition will complement the team.”

2. To provide what the partner lacks and lack what the partner provides, thus forming part of a whole.

   “The flavors of the pepper and garlic complement each other, giving a very rich taste in combination.”

   “I believe our talents really complement each other.”

3. To change a voltage, number, color, etc. to its complement.
4. Obsolete spelling or misspelling of compliment.