Synonyms to long established

acknowledged, admitted, chronic, confirmed, conventional, customary, deep-dyed, deep-engraven, deep-fixed, deep-grounded, deep-laid, deep-rooted, deep-seated, deep-set, deep-settled, dyed-in-the-wool, embedded, embossed, engrafted, engraved, entrenched, established, etched, fast, firmly established, fixed, folk, graven, hallowed, handed down, heroic, hoary, immemorial, implanted, impressed, imprinted, incorrigible, inculcated, indelibly impressed, infixed, ingrained, ingrown, instilled, inveterate, inwrought, irreversible, legendary, long-standing, mythological, of long standing, of the folk, old-line, on a rock, on bedrock, oral, prescriptive, received, recognized, rooted, set, settled, settled in habit, stabilized, thorough, time-honored, traditional, tried and true, true-blue, understood, unwritten, venerable, vested, well-established, well-founded, well-grounded, well-set, well-settled, worshipful