Other forms: throbbing; throbbed; throbs
Things that throb have a strong, regular pulse or rhythm. Loud music with a heavy beat or bass line can seem to throb inside your head — especially if your downstairs neighbors are playing it while you're trying to sleep.
Your heartbeat throbs especially fast when you're upset or just after you've been running, and something painful can throb too, like the ache of a stubbed toe. No one's exactly sure where the word throb comes from — most experts guess that it originated as a representation of the sound and feeling of your pulse.