Casca's last in revolt to step up (5)
I believe the answer is:
raise
'step up' is the definition.
'raise' can be an answer for 'step' (thesaurus). I am not sure about the 'up' bit.
'casca's last in revolt' is the wordplay.
'last' says to take the final letters.
'in' indicates putting letters inside.
'revolt' becomes 'rise' (I've seen this in another clue).
The final letter of 'casca' is 'a'.
'a' inserted within 'rise' is 'RAISE'.
'to' is the link.
Can you help me to learn more?
(Other definitions for raise that I've seen before include "Exalt" , "rally" , "Put up" , "Increase; elevate" , "cairn" .)