Cut from octopus - sorry about that! (4)
I believe the answer is:
oops
'sorry about that' is the definition.
'oops' can be an answer for 'sorry' (I've seen this before). I am unsure of the rest of the definition.
'cut from octopus' is the wordplay.
'from' is a deletion indicator.
'octopus' with 'cut' taken out is 'OOPS'.
Can you help me to learn more?
(Other definitions for oops that I've seen before include "Something's been spilt!" , "The sound of stupidity" , "I've messed up" , "Exclamation after mistake or minor accident" , "My bad" .)