1) Drawn-out 2) Extended 3) Lengthened or extended 4) Lengthy 5) Long 6) Prolonged 7) Relatively long in duration 8) Tediously protracted Found on https://www.crosswordclues.com/clue/protracted
Pro·tract`ed adjective Prolonged; continued. Protracted meeting , a religious meeting continued for many successive days. [ U. S.] -- Pro*tract'ed*ly , adverb -- Pro*tract'ed*ness , noun Found on http://www.encyclo.co.uk/webster/P/182