Com"ple*ment (?), *n.* [L.
*complementun*: cf. F. *complément*. See
__Complete__, *v. t.*, and cf.
__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.** *(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.]
*Shak.*

**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 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.Com"ple*ment (?), *v. t.*
**1.** To supply a lack; to supplement.
[R.]

**2.** To compliment. [Obs.] *Jer.
Taylor.*