We don't have synonyms for colters yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are colter, coulters and copters.
(n) :
(American spelling) Alternative spelling of coulter. [A cutter, consisting of a blade in either knife form or disk form, attached to the ploughbeam of a plough to cut the sward, in front of the ploughshare and mouldboard.]
(n) :
(American spelling) Alternative spelling of coulter. [A cutter, consisting of a blade in either knife form or disk form, attached to the ploughbeam of a plough to cut the sward, in front of the ploughshare and mouldboard.]