Wiktionary
vb. (present participle of drop off English)
Usage examples of "dropping off".
Dick was just dropping off when he heard something coming wriggling through the heather.
He did not put it up, however, and she thought that he was dropping off to sleep.
Besides, the latter and Kennedy were dropping off their feet with fatigue.
It is not proper for man's life to be a circle, she thought, or a string of circles dropping off like zeros behind him—.
He searched for his hay-cork, found it, stuck it in harder, and was just dropping off once more, when, pop!
The entire cavern seemed to shake as stalactites rained from the ceiling, then the granite bridge cracked, large pieces dropping off.
He could not recall dropping off to sleep, but he had awoken refreshed and now he stretched and rose.