The usage of the word
already as a semi-
phatic particle in the sense gratuitously slagged off (and misinterpreted) by
e-troon above (where
BE would probably use "then", with a similar non-implication of "subsequently") stems largely from the influence of
German and
Yiddish schon and
Italian già which both share this usage and the temporal meaning ("your
prescriptive ideas about linguistic usage have already been discarded").
However, more to the point, language use is a moving target, and words mean what people use them to mean. The evidence of a dictionary nearly a century old says little about the meaning(s) of a word today, or changes in their geographical distribution.