Source : Webster's Revised Unabridged Dictionary (1913)

Biweekly \Bi"week`ly\, a. [Pref. bi- + weekly.]
   Occurring or appearing once every two weeks; fortnightly. --
   n. A publication issued every two weeks. -- {Bi"week"ly},
   adv.

Biweekly \Bi"week`ly\, a. [Pref. bi- + weekly.]
   Occurring or appearing once every two weeks; fortnightly. --
   n. A publication issued every two weeks. -- {Bi"week"ly},
   adv.

Source : WordNet®

biweekly
     adj 1: occurring twice a week [syn: {semiweekly}]
     2: occurring every two weeks [syn: {fortnightly}]
     n : a periodical that is published biweekly
     adv 1: twice a week; "he called home semiweekly" [syn: {semiweekly}]
     2: every two weeks; "he visited his cousins fortnightly" [syn:
        {fortnightly}]