drug store n.

late 14c., drogge (early 14c. in Anglo-French), "any substance used in the composition or preparation of medicines," from Old French droge "supply, stock, provision" (14c.), which is of unknown origin. Perhaps it is from Middle Dutch or Middle Low German droge-vate "dry barrels," or droge waere, literally "dry wares" (but specifically drugs and spices), with first element mistaken as indicating the contents, or because medicines mostly consisted of dried herbs.

Compare dry goods(1708), so called because they were measured out in dry (not liquid) measure, and Latin species, in Late Latin "wares," then specialized to "spices" (French épice, English spice). The same source produced Italian and Spanish droga, Swedish drog.

Specific application to "narcotics and opiates" is by late 19c., though the association of the word with "poisons" is from 1500s. Druggie "drug addict" is recorded by 1968. Phrase a drug on (or in) the market "thing which has lost its value and is no longer wanted" (mid-17c.) is of doubtful connection and may be a different word, perhaps a play on drag, which was sometimes written drug c. 1240-1800.

c. 1300, "supplies or provisions for a household, camp, etc.," from store (v.) or else from Old French estore "provisions; a fleet, navy, army," from estorer or from Medieval Latin staurum, instaurum "store." General sense of "sufficient supply" is attested from late 15c. The meaning "place where goods are kept for sale" is first recorded 1721 in American English (British English prefers shop (n.)), from the sense "place where supplies and provisions are kept" (1660s).

The word store is of larger signification than the word shop. It not only comprehends all that is embraced in the word shop, when that word is used to designate a place in which goods or merchandise are sold, but more, a place of deposit, a store house. In common parlance the two words have a distinct meaning. We speak of shops as places in which mechanics pursue their trades, as a carpenter's shop a blacksmith's shop a shoemaker's shop. While, if we refer to a place where goods and merchandise are bought and sold, whether by wholesale or retail, we speak of it as a store. [C.J. Brickell, opinion in Sparrenberger v. The State of Alabama, December term, 1875]

Stores "articles and equipment for an army" is from 1630s. In store "laid up for future use" (also of events, etc.) is recorded from late 14c. Store-bought is attested from 1912, American English; earlier store-boughten (1872).