Unambiguous act has cruel repercussions (5-3)
I believe the answer is:
clear-cut
'unambiguous' is the definition.
(I've seen this before)
'act has cruel repercussions' is the wordplay.
'act' becomes 'cut' (cut is a kind of act).
'has' means one lot of letters go next to another.
'cruel repercussions' becomes 'clear' (I can't explain this - if you can you should believe this answer much more).
'cut' after 'clear' is 'CLEAR-CUT'.
Can you help me to learn more?
(Other definitions for clear-cut that I've seen before include "Free from obscurity" , "Distinct and sharply-defined" , "Very distinct, not open to doubt" , "Definite - 2 down" , "Decisive" .)