backlog

American  

[bak-lawg, -log] / ˈbækˌlɔg, -ˌlɒg /

noun

1. a reserve or accumulation, as of stock, work, or business.

   a backlog of business orders.

   Synonyms:

   reservoir, cache, fund, store, stock, supply

2. a large log at the back of a hearth to keep up a fire.

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verb (used with object)

backlogged, backlogging

1. to hold in reserve, as for future handling or repair.

2. to enter and acknowledge (an order) for future shipment.

verb (used without object)

backlogged, backlogging

1. to accumulate in a backlog.

   Orders are starting to backlog faster than we can process them.

backlog British  

/ ˈbækˌlɒɡ /

noun

1. an accumulation of uncompleted work, unsold stock, etc, to be dealt with

2. a large log at the back of a fireplace

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Etymology

Origin of backlog

First recorded in 1675–85; back ¹ + log ¹

Explanation

When you have extra work to do that keeps accumulating, you have a backlog. Sometimes people stay late at their jobs to take care of a backlog. A backlog of tasks might slow down an ordinary day at an office or store, or require workers to come in on the weekend to catch up. In 1680, a backlog meant "a large log placed at the back of a fireplace," and by the 1880s it came to also mean "something stored for later use." It wasn't until the early 20th century that a backlog most often referred to "extra unfulfilled orders."

Example Sentences

It would take weeks, if not months, to begin clearing the backlog in the Gulf.

From The Wall Street Journal • Apr. 19, 2026

The backlog of afflictions in the waiting room include severe sunburn…

From The Wall Street Journal • Apr. 17, 2026

CoreWeave reported a revenue backlog of $66.8 billion at the end of 2025, and its recent deals appear to have boosted that metric to over $90 billion.

From MarketWatch • Apr. 16, 2026

The backlog is expected to rise to more than 100,000 by the end of this year and it is predicted there could be 200,000 cases waiting to be heard by 2035 if nothing changes.

From BBC • Apr. 9, 2026

She also had to sort through the unit’s massive backlog of paperwork.

From "The Woman All Spies Fear" by Amy Butler Greenfield

Related Words

• inventory
• stockpile