Source : Webster's Revised Unabridged Dictionary (1913)

Tern \Tern\, a. [L. pl. terni three each, three; akin to tres
   three. See {Three}, and cf. {Trine}.]
   Threefold; triple; consisting of three; ternate.

   {Tern flowers} (Bot.), flowers growing three and three
      together.

   {Tern leaves} (Bot.), leaves arranged in threes, or three by
      three, or having three in each whorl or set.

   {Tern peduncles} (Bot.), three peduncles growing together
      from the same axis.

   {Tern schooner} (Naut.), a three-masted schooner.