deadlock

A situation that arises when two threads each acquires the lock to one of a set of resources that they both need.

Unresolved contention for the use of a system or component. [From Weik '89] 2. In computer and data processing systems, an error condition such that processing cannot continue because each of two components or processes is waiting for an action or response from the other. [From Weik '89] 3. A permanent condition in which a system cannot continue to function unless some corrective action is taken. [From Weik '89]