Jitter is {TAIL ~ a type} of timing error between the expected or ideal timing of {HEAD ~ a signal} and the actual timing of a signal in which the characteristics of the timing error change with time 
Jitter is { TAIL ~ a type } of timing error between the expected or ideal timing of { HEAD ~ a signal } and the actual timing of a signal in which the characteristics of the timing error change with time
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH