During the weekend, walk in open areas (6)
I believe the answer is:
spaces
'open areas' is the definition.
(I've seen this before)
'during the weekend walk' is the wordplay.
'during' indicates putting letters inside.
'the weekend' becomes 'SS' (abbreviations for Saturday and Sunday).
'walk' becomes 'pace' (pacing is a kind of walking).
'ss' placed around 'pace' is 'SPACES'.
'in' acts as a link.
(Other definitions for spaces that I've seen before include "Empty areas" , "distances" , "Gaps" , "Blank areas" , "boxes" .)