The boy is a little shorter than the woman (3)
I believe the answer is:
lad
'the boy' is the definition.
(informal term for boy)
'a little shorter than the woman' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'little' could be 'l' (abbreviation for little) and 'l' is located in the answer.
A single letter 'd' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'is' is the link.
Can you help me to learn more?
(Other definitions for lad that I've seen before include "Stable employee" , "Chap, fellow" , "Shaver" , "Scottish lover" , "Youngster" .)