Retreat that's a pretence, accepting resistance (6)
I believe the answer is:
ashram
'retreat' is the definition.
(I've seen this before)
'a pretence accepting resistance' is the wordplay.
'pretence' becomes 'sham' (I've seen this before).
'accepting' is an insertion indicator.
'resistance' becomes 'r' (abbreviation).
'sham' going around 'r' is 'shram'.
'a'+'shram'='ASHRAM'
'that's' acts as a link.
(Other definitions for ashram that I've seen before include "Hindu hermitage" , "Hindu religious retreat" , "holy man's retreat" , "Hindu place of retreat" , "Place for religious retreat (in India)" .)