backfillverb
/ˈbæk.fɪl/backfill verb (MATERIAL)
[ I or T ] to fill a hole created by digging or drilling, especially using some of the material that has been taken out:
Dig a large hole for the plant, then backfill with soil and compost.
Finally, backfill the trench.
backfill verb (JOBS)
[ T ] to replace workers after jobs have been made available:
Chrysler says it intends to backfill jobs vacated by the buyouts.
backfillnoun [ U ]
/ˈbæk.fɪl/material used to fill a hole that has been created by digging, etc.:
Some of the fluorite produced from the lead mines was used as backfill underground.