speedspeedspeedsspedspeededspeeding2verb (speeds, speeding, spedor speeded, has spedor has speeded)1to go or move very quickly: He sped past me on his bike.2to drive too fast: The police stopped me because I was speeding.speed up, speed something upto go faster; to make something go faster: What can we do to speed up the process?speedspeedspeeds1nounhow fast something goes: The car was travelling at a speed of 50 miles an hour.a high-speed train (= that goes very fast)