Pleach \Pleach\, v. t. [imp. & p. p. {Pleached}; p. pr. & vb. n. {Pleaching}.] [Cf. OF. plaissier to bend, and also F. plisser to plait, L. plicare, plicitum, to fold, lay, or wind together. Cf. {Plash} to pleach.] To unite by interweaving, as branches of trees; to plash; to interlock. ``The pleached bower.'' --Shak.