Adult in Switzerland rented house (6)
I believe the answer is:
chalet
'house' is the definition.
(chalet is a kind of house)
'adult in switzerland rented' is the wordplay.
'adult' becomes 'a'.
'in' indicates putting letters inside.
'switzerland' becomes 'ch'.
'rented' becomes 'let' (I've seen this before).
'ch'+'let'='chlet'
'a' going into 'chlet' is 'CHALET'.
(Other definitions for chalet that I've seen before include "Swiss hut for mountaineers" , "The lac (anag.)" , "Swiss hut or cottage" , "wooden hut" , "holiday accommodation" .)