lig·a·ture 
(lĭgə-chr′, -chər)
(lĭgə-chr′, -chər)n.
1. The act of tying or binding.
2.
a. A cord, wire, or bandage used for tying or binding.
b. A thread, wire, or cord used in surgery to close vessels or tie off ducts.
c. Something that unites; a bond.
3. A character, letter, or unit of type, such as æ, combining two or more letters.
4. Music
a. A group of notes intended to be played or sung as one phrase.
b. A curved line indicating such a phrase; a slur.
c. A passage of notes sung by repeating the same syllable.
d. A metal band that attaches the reed to the mouthpiece of the clarinet and related instruments.
tr.v. lig·a·tured, lig·a·tur·ing, lig·a·tures
To ligate.
[Middle English, from Old French, from Late Latin ligātūra, from Latin ligātus, past participle of ligāre, to bind; see leig- in the Appendix of Indo-European roots.]
ligatureopening notes of "The Star-Spangled Banner"