ligature
lig.a.ture \'lig-*-.chu.(*)r, -ch*r, -.t(y)u.(*)r\ n [ME, fr. MF, fr. LL ligatura, fr. L ligatus, pp. of ligare to] bind, tie; akin to MHG geleich joint, Alb lith I tie 1a: something that is used to bind; specif : a filament (as a threa d) used in surgery 1b: something that unites or connects : BOND 2: the action of binding or tying 3: a compound note in mensural notation indicating a group of musical notes to be sung to one syllable 4: a printed or written character consisting of two or more letters or char acters united (as)
Webster's English Dictionary