jit ‧ ter ‧ bug /ˈdʒɪtəbʌɡ $ -ər-/ BrE AmE noun [singular]
[ Date: 1900-2000 ; Origin: jitter 'to move quickly and nervously' (1900-2000) (from jitters ) + bug 'person with a strong interest in something' (19-21 centuries) ; probably invented by the U.S. band leader Cab Calloway ]
a fast ↑ jazz dance popular in the 1940s