Tenacious
WordNet
adjective
(1) Sticking together
"Two coherent sheets"
"Tenacious burrs"
(2) Good at remembering
"A retentive mind"
"Tenacious memory"
(3) 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"