What is the meaning of drowsing?

verb

• Sleep lightly or for a short period of time.
  • synonyms: snooze, drowse, doze
• Be on the verge of sleeping.
  • usage: "The students were drowsing in the 8 AM class"
  • synonyms: drowse

adjective

• Half asleep)
  • usage: "made drowsy by the long ride"; "it seemed a pity to disturb the drowsing (or dozing) professor"; "a tired dozy child"; "the nodding (or napping. grandmother in her rocking chair"
  • synonyms: drowsy, dozy