Square meal with no starter for lunch (4)
I believe the answer is:
four
'square' is the definition.
(four is a square number)
'meal with no starter for lunch' is the wordplay.
I cannot quite understand how this works, but
'no' could be 'o' (O resembles 0) and 'o' is located in the answer.
The remaining letters 'fur' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for four that I've seen before include "IV in Roman numerals" , "Square number" , "Figure" , "10 cleared of misuse of fortune" , "Rowing boat; number" .)