1) Biweekly 2) Every two weeks 3) Occurring every two weeks 4) Period 5) Period of time 6) Time period 
• (a.) Occurring or appearing once in a fortnight; as, a fortnightly meeting of a club; a fortnightly magazine, or other publication. • (adv.) Once in a fortnight; at intervals of a fortnight.
Fort'night`ly adjective Occurring or appearing once in a fortnight; as, a fortnightly meeting of a club; a fortnightly magazine, or other publication. -- adverb Once in a fortnight; at intervals of a fortnight. 
[adj] - occurring every two weeks 2. [adv] - every two weeks
biweekly adjective occurring every two weeks