Sand-boy? (6)
I believe the answer is:
martin
'boy?' is the definition.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for martin that I've seen before include "Variety of swallow" , "Bird; in tram (anag.)" , "Bird or boy's name" , "Martyred civil rights leader" , "Tweeter" .)