intransitive verb. 
                    To tremble; to vibrate; to shake.
                  
                
                  
                    intransitive verb. 
                    Especially, to shake the voice; to utter or form sound with rapid or tremulous vibrations, as in singing; also, to trill on a musical instrument.
                  
                
                  
                    noun. 
                    A shake, or rapid and tremulous vibration, of the voice, or of an instrument of music.
                  
                
                  
                    noun. 
                    An eighth note. See Eighth.
                  
                
                  
                    transitive verb. 
                    To utter with quavers.