Assignation shown to be impossible? (7)
I believe the answer is:
mission
'assignation' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for mission that I've seen before include "religious establishment" , "In religious campaign" , "Vocation; embassy" , "Assignment; expedition" , "Delegation" .)