sub-millisecond From sub- + millisecond. <span class="searchmatch">submillisecond</span> (not comparable) Lasting less than a millisecond...
(not comparable) (physics) Of or pertaining to time spans of less than a femtosecond subfemtosecond intervals subnanosecond submicrosecond <span class="searchmatch">submillisecond</span>...