\Tri"week`ly\, a. [Pref. tri- + weekly.]
Occurring or appearing three times a week; thriceweekly; as,
a triweekly newspaper. -- adv. Three times a week. -- n. A
triweekly publication.
Note: This is a convenient word, but is not legitimately
      formed. It should mean occurring once in three weeks,
      as triennial means once in three years. Cf. {Biweekly}.