Origin and history of wi-fi

1947, abbreviation of high-fidelity (1934), a descriptive term of radio receivers in reference to their quality of sound reproduction. Hi as an advertiser's phonological shortening of high (adj.) is attested by 1914. Fidelity in the sense "faithful reproduction of sound" is from 1878.

by 1862 of unstrung pianos, 1886 of bustles; by 1876 in reference to telegraphy and attempts to send signals without the use of wires (water was tried as a medium; on railway systems the rails themselves); from wire (n.) + -less.

Marconi's system went into use in 1897 and was instantly celebrated, and the word came to be applied to it. By 1900 it was applied to the still newer technology of sending articulate sounds (wireless telephony) and thus to radio sound broadcasting. Hence, as a noun, "radio broadcasting" (by 1903) "radio set" (by 1921).

Both subsequently were superseded by classically derived (and thus international) radio. The international agreement and protocol on wireless (Berlin, 1906) uses radio-telegraphy and radio:

"Wireless telegrams shall show in the preamble that the service is "wireless" ("radio")."

In early 1910s communications systems often are described as radio or wireless.