Sounds like a kind of square meal
I believe the answer is:
tea
'meal' is the definition.
(tea is a kind of meal)
'sounds like a kind of square' is the wordplay.
'sounds like' shows a homophone (sound like).
'a kind of square' becomes 'T' (a T-Square is a technical drawing instrument).
't' is a homophone of 'TEA'.
(Other definitions for tea that I've seen before include "Leaves for brewing" , "Infused beverage" , "For Japanese ceremony" , "Light afternoon repast" , "TREE" .)