leak

leak n.  With qualifier, one of a class of
   resource-management bugs that occur when resources are not freed
   properly after operations on them are finished, so they effectively
   disappear (leak out).  This leads to eventual exhaustion as new
   allocation requests come in.  {memory leak} and {fd leak}
   have their own entries; one might also refer, to, say, a `window
   handle leak' in a window system.