Activity with a suffix -eer?
Other than simple words (beer, career, cheer, deer, leer, queer, and sheer), the suffix form -eer is usually applied to persons (or their actions in the case of the verb "commandeer"). The root nouns or verbs establish the activity or locale for the individuals involved, e.g. "gazetteer", "mutineer" and "mountaineer". More esoteric is the science-fiction neologism "rocketeer".
The suffix -ist indicates a person involved in the activity or field (e.g. scientist works in science). The suffix is added to the root of a verb or noun form such as -ism, -ize or -ing. Examples : Someone who does cycling = cyclist Someone who apologizes = apologist Someone involved with feminism = feminist The suffix "ist" means "one who does." Florist, pianist, dentist, for example. It can also be used to show beliefs…