tri·week·ly (trī-wēk

lē)
adj.►  Happening, done, or appearing three times a week.
►  Happening, done, or appearing every three weeks.
adv.►  Three times a week.
►  Every three weeks.
n. pl. tri·week·lies A periodical published triweekly. 
 [TahlilGaran] American Dictionary ▲