1835 as a dish for a bar of soap; 1814 as a holder for shaving-soap, from soap (n.) + dish (n.).
Entries linking to soap-dish
soap n.
Middle English sope, from Old English sape "soap, salve," anciently a reddish hair dye used by Germanic warriors to give a frightening appearance, from Proto-Germanic *saipon "dripping thing, resin" (source also of Middle Low German sepe, West Frisian sjippe, Dutch zeep, Old High German seiffa, German seife "soap," Old High German seifar "foam," Old English sipian "to drip"), from PIE *soi-bon-, from root *seib- "to pour out, drip, trickle" (perhaps also the source also of Latin sebum "tallow, suet, grease").
Romans and Greeks used oil to cleanse the skin; the Romance words for "soap" (Italian sapone, French savon, Spanish jabon) are from Late Latin sapo "pomade for coloring the hair" (first mentioned in Pliny), which is a Germanic loan-word, as is Finnish saippua. The figurative meaning "flattery" is recorded from 1853.
dish n.
Old English disc "plate, bowl, platter," from Latin discus "dish, platter, quoit," in Medieval Latin "a table, dais, desk, pulpit," from Greek diskos "disk, platter" (see disk (n.)).
A common West Germanic borrowing; Old High German took the word as tisc "plate," but German Tisch now means "table," in common with some other later Romanic forms of Latin discus (such as Italian desco, French dais); compare desk (n.), dais.
Meaning "particular variety of food served in a dish" is first recorded mid-15c. Meaning "what one likes, what is suited to one's taste" is by 1918; that of "attractive woman" is 1920s. Meaning "concave reflector or antenna" attested from 1948.
Originally applied to very shallow or flat vessels, as plates and platters, the term now usually includes any large open vessel, more or less deep, and with or without a cover, used to contain food or table-drink such as tea, coffee, or chocolate. The use of the term to include drinking-vessels, as bowls and cups, is less common, and seems to be obsolescent, except as such vessels are included in the collective plural dishes. [Century Dictionary, 1897]