‖ hersillonObs. [F. hersillon, f.herse.] 1704J. Harris Lex.Techn., Hersillon, in Fortification, is a Plank stuck with Iron Spikes, for the same use as the Herse.1706Phillips (ed. Kersey), Hersillon, a Plank Ten or Twelve Foot long stuck full of Nails, with the points up.