What is the meaning of throbbing?

noun

• An instance of rapid strong pulsation (of the heart. )
  • usage: "he felt a throbbing in his head"
  • synonyms: throb, pounding
• A sound with a strong rhythmic beat.
  • usage: "the throbbing of the engines"

verb

• Pulsate or pound with abnormal force.
  • usage: "my head is throbbing"; "Her heart was throbbing"
  • synonyms: throb
• Expand and contract rhythmically; beat rhythmically.
  • usage: "The baby's heart was pulsating again after the surgeon massaged it"
  • synonyms: pulsate, throb, pulse
• Tremble convulsively, as from fear or excitement.
  • synonyms: shudder, shiver, throb, thrill

adjective

• Pounding or beating strongly or violently.
  • usage: "a throbbing pain"; "the throbbing engine of the boat"