noun / verb
backlog
BAK-lawg/ˈbæklɔːɡ/
A buildup of unfinished work or unmet demand, or to build up in this way.
The cobbler has a backlog of damaged shoes awaiting repair.

Etymology
Back + log first named a large log at the rear of a fire. The later senses of stored reserves and unfinished work may instead derive from, or have been suggested by, log meaning “record.”
In context
burndown charts show the progress during a Sprint on the completion of tasks in the Sprint backlog this chart should approach zero points as the work is being completed
More examples
- New applications began to backlog after the office lost staff.
- We worked late to clear the backlog.
- A month of orders remained backlogged.
Forms
backlog · backlogs · backlogged · backlogging
backlogged adjective — accumulated and awaiting completion
Similar words
- queue
- A queue is work waiting in order; a backlog emphasizes accumulated unfinished work.
- arrears
- Arrears are overdue obligations; a backlog need not yet be overdue.