Whether court case imprisons four or six, it's insignificant (7)
I believe the answer is:
trivial
'insignificant' is the definition.
(similar in meaning)
'whether court case imprisons four or six' is the wordplay.
I cannot quite see how this works, but
'four' could be 'iv' (Roman numerals) and 'iv' is found within the answer.
'court' could be 'trial' (trial court is a kind of court) and 'trial' is found within the remaining letters.
No letters remain.
This explanation may well be incorrect...
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for trivial that I've seen before include "Piddling" , "Banal" , "not significant" , "Quite unimportant and paltry" , "Frivolous" .)