When describing a task that isn't running, and can't yet be started, because one or more previous tasks haven't been completed, how can that task be concisely described?
The best I have is "blocked", but
The former task is waiting on or dependent upon or contingent upon the latter task's completion. However, consider a past ELU question involving "wait on".
Side note: in many technical domains, such as software development, block is perfectly normal, and largely free of negative connotation:
Once called, this procedure blocks on an input signal from the device.
(I use this often enough that I would have thought little of using it in an everyday context, until I read your question. I might hang out with too many geeks.)
Consider using the word "queued"; according to the free dictionary it already has a definition used in the computer world to mean precisely what you are trying to mean. For instance, if you are describing a process that is waiting on another process without going into detail as to why it is waiting, you can simply say "That process is currently queued," or "That process is in the queue." I know that in an application I use for processing database changes this is the word that is used.
