Scotsman loses capital, belonging to Mennonite sect (5)
I believe the answer is:
amish
'belonging to mennonite sect' is the definition.
(relating to the Amish people)
'scotsman loses capital' is the wordplay.
'scotsman' becomes 'Hamish' (common Scottish name).
'loses capital' means to remove the first letter.
'hamish' with its first letter removed is 'AMISH'.
(Other definitions for amish that I've seen before include "US religious community" , "US sectarians" , "American religious sect" , "American follower of the Mennonite religion" , "Community that settled in America" .)