Possible Definitions:
1. Complement (v. t.) That which fills up or completes; the quantity or number required to fill a thing or make it complete.
2. Complement (v. t.) That which is required to supply a deficiency, or to complete a symmetrical whole.
3. Complement (v. t.) Full quantity, number, or amount; a complete set; completeness.
4. Complement (v. t.) A second quantity added to a given quantity to make it equal to a third given quantity.
5. Complement (v. t.) Something added for ornamentation; an accessory.
6. Complement (v. t.) The whole working force of a vessel.
7. Complement (v. t.) The interval wanting to complete the octave; -- the fourth is the complement of the fifth, the sixth of the third.
8. Complement (v. t.) A compliment.
9. Complement (v. t.) To supply a lack; to supplement.
10. Complement (v. t.) To compliment.