·noun An adder or serpent.
II. Edder ·vt To bind the top interweaving edder; as, to edder a hedge.
III. Edder ·noun Flexible wood worked into the top of hedge stakes, to bind them together.
fence wood, commonly put on the top of fences. Norf. and Ess. ...
A glossary of provincial and local words used in England by Francis Grose