“Usage: The way in which the elements of language are customarily used to produce meaning, including accent, pronunciation, words, and idioms. The term occurs neutrally in formal usage, disputed usage, and local usage, and it has strong judgmental and prescriptive connotations in bad usage, correct usage, usage and abusage, and usage controversies.”
Excerpted from: McArthur, Tom. The Oxford Concise Companion to the English Language. New York: Oxford University Press, 2005.