Dry stone work's not so fashionable (6)
I believe the answer is:
trendy
'fashionable' is the definition.
(similar in meaning)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for trendy that I've seen before include "Informally in the latest fashion" , "following fashion" , "Modish" , "all the rage" , "Hot" .)