To make stable, firm, or sure; appoint; ordain; settle or fix unalterably.To put or fix on a firm basis; settle stably or fixedly; put in a settled or an efficient state or condition; inceptively, set up or found: as, his health is well established; an established reputation; to establish a person in business; to establish a colony or a university.To confirm or strengthen; make more stable or determinate.To confirm by affirmation or approval; sanction; uphold.To make good; prove; substantiate; show to be valid or well grounded; cause to be recognized as valid or legal; cause to be accepted as true or as worthy of credence; as, to establish one's claim or one's case; to establish a marriage or a theory.To fix or settle permanently, or as if permanently: with a reflexive pronoun.To settle, as property.In systematic biol., to give technical publication to; fix by publication in the nomenclatorial sense. See publication, 5.