Squarish-looking lad welcomes kiss (4)
I believe the answer is:
boxy
'squarish' is the definition.
(I've seen this in another clue)
'looking lad welcomes kiss' is the wordplay.
'looking lad' becomes 'boy' (I've seen this in another clue. I am not sure about the 'looking' bit.).
'welcomes' means one lot of letters goes inside another (in sense of 'invites in').
'kiss' becomes 'x' (X can represent a kiss).
'boy' enclosing 'x' is 'BOXY'.
Can you help me to learn more?
(Other definitions for boxy that I've seen before include "Having a square appearance" , "Squarish in shape" .)