Farm cuts weeds every second, laughing (6)
I believe the answer is:
amused
'laughing' is the definition.
(I've seen this in another clue)
'farm cuts weeds every second' is the wordplay.
'every second' indicates alternate letters (I've seen 'every second of' mean this).
'farm'+'cuts'+'weeds'='farmcutsweeds'
The alternating letters of 'farmcutsweeds' are 'AMUSED'.
(Other definitions for amused that I've seen before include "Beguiled" , "Kept someone entertained" , "Queen Victoria wasn't!" , "was entertaining" , "Pleasantly occupied" .)