legato

American Heritage® Dictionary of the English Language, Fourth Edition

1. adv. In a smooth, even style without any noticeable break between the notes. Used chiefly as a direction.
2. n. A legato passage or movement.

Century Dictionary and Cyclopedia

1. In music, in a smooth, connected manner, without breaks or pauses between successive tones: opposed to staccato. It is usually indicated by the word itself (or its abbreviation leg.), by a sweeping curve, or above or below the notes to be performed without break, or (for single notes and chords in the midst of staccato passages) by the mark or above or below.
2. n. A smooth, connected manner of performance, or a passage so performed. In singing and on wind-instruments a strict legato is produced only when more tones than one are made continuously by a single breath; on instruments with a keyboard, like the organ and the pianoforte, it is produced by holding each key until just as the next is struck; on bowed instruments it is produced by a continuous motion of the bow, either up or down.

Wiktionary

1. adv. music Smoothly, in a connected manner.
2. n. music A slur curve above or below a passage of notes indicating that they should be played in a legato manner.

GNU Webster's 1913

1. adj. (Mus.) Connected; tied; -- a term used when successive tones are to be produced in a closely connected, smoothly gliding manner. It is often indicated by a tie, thus �, �, or �, �, written over or under the notes to be so performed; -- opposed to staccato.

WordNet 3.0

1. adj. (music) without breaks between notes; smooth and connected
2. adv. connecting the notes; in music