Webster's Revised Unabridged Dictionary · 1913

Complement

Complement , noun

[Latin complementun: compare French complément. See Complete, transitive verb, and compare Compliment.]

1.
That which fills up or completes; the quantity or number required to fill a thing or make it complete.
2.
That which is required to supply a deficiency, or to complete a symmetrical whole.
History is the complement of poetry. — Sir J. Stephen
3.
Full quantity, number, or amount; a complete set; completeness.
To exceed his complement and number appointed him which was one hundred and twenty persons. — Hakluyt
4.
(Mathematics) A second quantity added to a given quantity to make it equal to a third given quantity.
5.
Something added for ornamentation; an accessory. [Obsolete]
Without vain art or curious complements. — Spenser
6.
(Nautical) The whole working force of a vessel.
7.
(Music) The interval wanting to complete the octave; -- the fourth is the complement of the fifth, the sixth of the third.
8.
A compliment. [Obsolete] — Shakespeare
Collocations (5)
Arithmetical compliment of a logarithm , See under Logarithm.
Arithmetical complement of a number (Mathematics) , the difference between that number and the next higher power of 10; as, 4 is the complement of 6, and 16 of 84.
Complement of an arc or Complement of an angle (Geometry) , the difference between that arc or angle and 90°.
Complement of a parallelogram (Mathematics) , See Gnomon.
In her complement (Heraldry) , said of the moon when represented as full.

Complement , transitive verb

1.
To supply a lack; to supplement. [Rare]
2.
To compliment. [Obsolete] — Jer. Taylor