Spoke about uprising, that is showing repentance (6)
I believe the answer is:
rueing
'showing repentance' is the definition.
Although both the answer and definition are present participle verbs, I cannot understand how one could define the other.
'spoke about uprising that is' is the wordplay.
'spoke' becomes 'rung' (synonyms).
'about' means one lot of letters goes inside another.
'uprising' says the letters should be written in reverse.
'that is' becomes 'ie' (synonyms).
'ie' reversed gives 'ei'.
'rung' enclosing 'ei' is 'RUEING'.
Can you help me to learn more?
(Other definitions for rueing that I've seen before include "Feeling regret" , "Bitterly regretting (longer spelling)" , "Feeling sorry for" .)