During resignation speech, cast out without finishing. That's unjust (10)
I believe the answer is:
iniquitous
'unjust' is the definition.
(thesaurus)
'during resignation speech cast out without finishing' is the wordplay.
I cannot really see how this works, but
'during' could be 'in' (I've seen this in other clues) and 'in' is located in the answer.
an anagram of 'out' is 'tou' which is within the answer.
This explanation may well be incorrect...
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for iniquitous that I've seen before include "Wicked" , "base" , "Highly unfair or immoral" .)