long-established (adjective) confirmed: habitual; rooted
Sinonime: abiding, agreed, arranged, certain, changeless, confirmed, definite, determinate, enduring, firm, in the bag, inflexible, planned, prearranged, settled, stated,
stubborn, sure, unalterable,
uncompromising, unwavering
Antonime: indefinite, infrequent,
sporadic, uncommitted, unconfirmed,
undecided