Cheat with stoneworker, faithful (8)
I believe the answer is:
constant
'faithful' is the definition.
(associated in meaning)
'cheat with stoneworker' is the wordplay.
I cannot really understand how this works, but
'cheat' could be 'con' (con is a kind of cheat) and 'con' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for constant that I've seen before include "Steadfast or unvarying" , "Always - faithful" , "Perpetual" , "staying the same" , "Loyal - firm" .)