Definition of "loggerheads"

loggerheads

noun
1. plural of loggerhead
2. Fisticuffs; fighting.
3. (dialect) The knapweed.
  Quotations
  Loggerheads is a local term for a harmless plant called the knapweed (centaurea nigra) […]
  1912, Arnold Bennett, “Why the Clock Stopped”, in The Matador of the Five Towns and Other Stories, page 262