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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.
of or relating to the body of Protestant Christianity arising during the Reformation; used of some Protestant churches especially Calvinist as distinct from Lutheran; "Dutch Reformed theology"