Druggist, pharmacist, apothecary, chemist denote one who deals in medicinal drugs.
Druggist is the broadest of these terms and may designate a seller of drugs or medicinal preparations at wholesale or retail and as owner, manager, or employee of the sales establishment; it may often replace the more precise pharmacist to denote one who is skilled in compounding drugs and dispensing medicines prescribed by a physician especially when he is thought of primarily as selling these.
Pharmacist, however, specifically implies, as druggist does not, special training in pharmacy, professional standing, and usually licensing following a test of qualifications.
Apothecary in early use was distinguished from druggist, which then designated one who sold crude drugs (as herbs, roots, and other ingredients of medicines) while apothecary designated one who compounded these ingredients or made them up into medicines and was, therefore, equivalent to pharmacist.
The distinction has tended to disappear and apothecary may be interchangeable with either druggist or pharmacist although it is increasingly rare except in historical situations. In England chemist is the preferred term.