drowse
verb [intransitive]to be in a light sleep or almost asleep 打瞌睡；打盹；假寐 My mother was sitting on the porch drowsing in the sun. 我妈妈坐在门廊上，在阳光下打瞌睡。 We drowsed fitfully throughout the night. 我们整夜断断续续地打瞌睡。
Word Originlate 16th cent.: back-formation from drowsy.