difficult to accomplish; demanding considerable mental effort and skill; "the arduous work of preparing a dictionary"
characterized by toilsome effort to the point of exhaustion; especially physical effort; "worked their arduous way up the mining valley"; "a grueling campaign"; "hard labor"; "heavy work"; "heavy going"; "spent many laborious hours on the project"; "set a punishing pace"
taxing to the utmost; testing powers of endurance; "his final, straining burst of speed"; "a strenuous task"; "your willingness after these six arduous days to remain here"- F.D.Roosevelt
based on or having the nature of an illusion; "illusive hopes of finding a better job"; "Secret activities offer presidents the alluring but often illusory promise that they can achieve foreign policy goals without the bothersome debate and open decision that are staples of democracy"
highly important to or an integral part of a strategy or plan of action especially in war; "a strategic chess move"; "strategic withdrawal"; "strategic bombing missions"
relating to or concerned with strategy; "strategic weapon"; "the islands are of strategic importance"; "strategic considerations"
not as expected; "there was something fishy about the accident"; "up to some funny business"; "some definitely queer goings-on"; "a shady deal"; "her motives were suspect"; "suspicious behavior"
of or relating to or resembling fish; "the soup had a fishy smell"