I. ˈ ̷ ̷ˌ ̷ ̷ transitive verb
Etymology: back (II) + fill
: to replace earth in (as a trench or the open space around a foundation wall) ; also : to refill (as an excavation) with any material
II. noun
( -s )
1. : the refilling of a trench or other excavation or of the space around a foundation
2. : the material used in backfilling