Something cutting your thistles, having edges, first and foremost?? (6)
I believe the answer is:
scythe
'foremost??' is the definition.
I can't tell whether this defines the answer.
'something cutting your thistles having edges first' is the wordplay.
'first' says to take the initial letters.
The first letters of 'something cutting your thistles having edges' is 'SCYTHE'.
'and' acts as a link.
(Other definitions for scythe that I've seen before include "what the reaper holds" , "Old hand-held cutter of hay" , "Old hands-wielded grass or crop cutter" , "Reaper's implement" , "Old grass cutter with long handle and curved blade" .)