What does "trill" mean?

Trill: A sound, of consonantal character, made with a rapid succession of partial or entire intermissions, by the vibration of some one part of the organs in the mouth -- tongue, uvula, epiglottis, or lip -- against another part; as, the r is a trill in most languages.

Additional senses

  1. 2.The action of the organs in producing such sounds; as, to give a trill to the tongue. d 3. (Mus.) A shake or quaver of the voice in singing, or of the sound of an instrument, produced by the rapid alternation of two contiguous tones of the scale; as, to give a trill on the high C. See Shake.

Sources