noun A rapid alternation between an indicated note and the one above it as an ornament; in musical notation usually indicated with the letters tr written above the staff.
noun A type of consonantal sound that is produced by vibrations of the tongue against the place of articulation: for example, Spanish ⟨rr⟩, /r/.
noun A tremulous high-pitched vocal sound produced by cats.
verb To create a trill sound; to utter trills or a trill; to play or sing in tremulous vibrations of sound; to have a trembling sound; to quaver.
verb To impart the quality of a trill to; to utter as, or with, a trill.