1) Accumulated work 2) Accumulation 3) Accumulation at the factory 4) Aggregation 5) Arrears of work 6) Assemblage 7) Buildup of unfinished work 8) Collection 9) In-box pileup 10) Unfilled orders 11) Unprocessed orders 12) Unshipped inventory 13) Work yet to be done 1) Accumulation 2) Stockpile 
Backlog generally refers to an accumulation over time of work waiting to be done or orders to be fulfilled. Backlog may also refer to: ...
• (n.) A large stick of wood, forming the back of a fire on the hearth.
[Noun] Work that has built up and needs to be done now.
Back'log` (-lŏg`; 115) noun [ Back , adjective + log .] A large stick of wood, forming the back of a fire on the hearth. [ U.S.] « There was first a backlog , from fifteen to four and twenty inches in diameter and five feet long, imbedded in the ashes. S. G. Goodric...
Number of pending cases exceeding the capacity of a court which is engaged in acting on other cases.
[n] - large log at the back of a hearth fire 2. [n] - an accumulation of jobs not done or materials not processed that are yet to be dealt with 3. [v] - accumulate and create a backlog
noun an accumulation of jobs not done or materials not processed that are yet to be dealt with (especially unfilled customer orders for products or services)