Crossword puzzle clue "preservers"

CRUISE, to progress smoothly

CURER, one who cures

DOUGHNUT, to surround a speaker to give the impression of a packed house, also DONUT

ECOLOGIST, a student of ecology, also OECOLOGIST

GAMEKEEPER, a person in charge of the breeding and protection of game animals or birds on a private preserve

HERBARIUM, a collection of preserved plants and herbs