Small red wine lecturer replaced with another red (7)
I believe the answer is:
scarlet
'red' is the definition.
(I've seen this before)
'small red wine lecturer replaced with another' is the wordplay.
I cannot quite understand how this works, but
'small' could be 's' (abbreviation - e.g. clothes size) and 's' is present in the answer.
'lecturer' could be 'l' and 'l' is found within the answer.
'another' could be 're' (I've seen this in other clues) and 're' is found within the leftover letters.
The remaining letters 'cat' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for scarlet that I've seen before include "Murderer" , "Let cars be this colour" , "bloody?" , "Bright red of clarets" , "Vivid red" .)