Objective action? (4)
I believe the answer is:
case
This might be a double definition.
'objective' is the first definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'action?' is the second definition.
(synonyms)
Can you help me to learn more?
(Other definitions for case that I've seen before include "Police investigation" , "Cover" , "Action taken" , "proceedings" , "Piece of luggage and a lawyer's proceeding" .)