BACKFILL

Etymology

Verb

backfill (third-person singular simple present backfills, present participle backfilling, simple past and past participle backfilled)

To refill a hole with the material dug out of it.

(archaeology) To refill an excavation unit to restore the former ground surface and/or to preserve the unit and make it recognizable as having been excavated.

• We backfilled the cistern with pea gravel to discourage its use as a refuse container.

(US) To provide reserve support.

(US) To replenish or restock due to attrition or loss.

Noun

backfill (countable and uncountable, plural backfills)

The material that has been used to refill an excavation.

(US) Reserve support personnel.

(US) That which backfills; a replacement.

(literature) Material in a story set earlier in the past, providing history or context for the current action.

Source: Wiktionary