Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class VI. Words Relating to the Sentient and Moral Powers
Section III. Sympathetic Affections
1. Social Affections

891. Enemy.

   NOUN:ENEMY; antagonist; foe, foeman; open -, bitter- enemy; opponent [See Opponent]; backfriend [obs.], copemate or copesmate [obs.], “dearest foe”; mortal -aversion, – antipathy; snake in the grass.
  PUBLIC ENEMY, enemy to society; anarchist, seditionist, traitor, traitress (fem.).
  1. Every hand being against one.
  2. He makes no friend who never made a foe.—Tennyson