Merriam-Webster's Collegiate® Dictionary, 11th Edition
JAZZ
I. noun
Usage: often attributive
Etymology: origin unknown
Date: 1913
1. American music developed especially from ragtime and blues and characterized by propulsive syncopated rhythms, polyphonic ensemble playing, varying degrees of improvisation, and often deliberate distortions of pitch and timbre, popular dance music influenced by jazz and played in a loud rhythmic manner, empty talk ; humbug , similar but unspecified things ; stuff , jazzlike adjective
II. verb
Date: 1917
transitive verb
1. enliven , accelerate , to play in the manner of jazz, intransitive verb to go here and there ; gad , to dance to or play jazz