He shows some maladjustment (3)
I believe the answer is:
lad
'he' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'some maladjustment' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'LAD' is hidden within 'maladjustment'.
'shows' is the link.
Can you help me to learn more?
(Other definitions for lad that I've seen before include "Stable worker" , "Son" , "Boy, young man" , "Scottish lover" , "Shaver" .)