DOWN n.
A road for shipping in the English Channel or Straits of Dover, near Deal, employed as a naval rendezvous in time of war. On the 11th [June, 1771] we run up the channel . . . at noon we were abreast of Dover, and about three came to an anchor in the Downs, and went ashore at Deal. Cook (First Voyage).…
EN- n.
or in-. For ease of pronunciation it is commonly changed to em- before p, b, and m, as in employ, embody, emmew. It is sometimes used to give a causal force, as in enable, enfeeble, to cause to be, or to make, able, or feeble; and sometimes merely gives an intensive force, as in enchasten. See In-.