Trick monster briefly used for domination (7)
I believe the answer is:
control
'domination' is the definition.
(thesaurus)
'trick monster briefly used' is the wordplay.
'trick' becomes 'con' (I've seen this before).
'monster' becomes 'tr' (I can't explain this - if you can you should believe this answer much more).
'briefly' means to remove the last letter.
'used' becomes 'old' ('old' can be similar in meaning to 'used').
'old' with its last letter taken away is 'ol'.
'con'+'tr'+'ol'='CONTROL'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for control that I've seen before include "Mastery" , "Exercise power over" , "Influencing power" , "Rein" , "Authority" .)