"haunting memories"
"the cathedral organ and the distant voices have a haunting beauty"
retained; not shed;
"persistent leaves remain attached past maturity"
"the persistent gills of fishes"
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"
"men tenacious of opinion"