Com·ple·ment n.
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. Math. A second quantity added to a given quantity to make it equal to a third given quantity.
5. Something added for ornamentation; an accessory. [Obs.]
Without vain art or curious complements. --Spenser.
6. Naut. The whole working force of a vessel.
7. Mus. The interval wanting to complete the octave; -- the fourth is the complement of the fifth, the sixth of the third.
8. A compliment. [Obs.]
Arithmetical compliment of a logarithm. See under Logarithm.
Arithmetical complement of a number Math., 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 Geom., the difference between that arc or angle and 90°.
Complement of a parallelogram. Math. See Gnomon.
In her complement Her., said of the moon when represented as full.