backfill

American  

[bak-fil] / ˈbækˌfɪl /

noun

1. material used for refilling an excavation.

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verb (used with object)

1. to refill (an excavation).

2. to make up for a loss or shortfall of supplies or funds.

   It is illegal to backfill the state budget with federal emergency funds.

3. to fill (a recently vacated position), often with an internal candidate or temp.

backfill British  

/ ˈbækˌfɪl /

verb

1. (tr) to refill an excavated trench, esp (in archaeology) at the end of an investigation

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noun

1. the soil used to do this

Etymology

Origin of backfill

First recorded in 1950–55; back ² + fill

Example Sentences

If there is a shortfall, there’s about $840 billion in revenue from businesses—entities without claims to clean consciences—raised through customs and corporate income taxes that could be used as morally inert backfill.

From Slate • May 11, 2026

“Frontier, JetBlue, and United all made concerted efforts to backfill Spirit’s markets out of Florida” after Spirit filed its second bankruptcy in September, the analyst continued.

From Barron's • May 1, 2026

Federal funds account for $2.4 billion of California’s $5.3-billion public health budget, making it difficult for Newsom and state lawmakers to backfill potential cuts.

From Los Angeles Times • Mar. 9, 2026

"Businesses need to control the money to prevent local authorities using it to backfill the reduction in services."

From BBC • Dec. 3, 2025

Williams, who is now New York Fed president, cited alternate data sources to backfill one government data report on inflation that was late.

From The Wall Street Journal • Oct. 16, 2025