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adj.
stubbornly unyielding; "dogged persistence"; "dour determination"; "the most vocal and pertinacious of all the critics"; "a mind not gifted to discover truth but tenacious to hold it"- T.S.Eliot; "men tenacious of opinion"
adj.
stubbornly defiant of authority or restraint: "an obstreperous almost mutinous crew"; "the University suspended the most recalcitrant demonstrators"; "a truculent speech against the new government"