Dwelling for occasional use (4-1-5)
I believe the answer is:
pied-a-terre
'dwelling for occasional use' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for pied-a-terre that I've seen before include "Dwelling for occasional use" , "Lodging kept for occasional use (French)" , "Small secondary flat or house" , "bijou accommodation" , "Small home kept for occasional use" .)