"pertaining to Oxford or to Oxford University," 1640s, from Medieval Latin oxonia, Latinized form of Middle English Oxforde (see Oxford). Earlier as a noun, "native or inhabitant of Oxford" (1540s).
Entries linking to oxonian
Oxford
university town in England, Middle English Oxforde, from Old English Oxnaforda (10c.) literally "where the oxen ford" (see ox + ford (n.)). In reference to a type of shoe laced over the instep, it is attested from 1721 (Oxford-cut shoes). In reference to an accent supposedly characteristic of members of the university, by 1855. Related: Oxfordian; Oxfordish; Oxfordist; Oxfordy.
Oxford comma for "serial comma" (the second in A, B, and C) is attested by 1990s, from its being used by Oxford University Press or its recommendation by Henry W. Fowler, long associated with Oxford University, in his influential and authoritative book on English usage (1926) in which he writes "there is no agreement at present on the punctuation," but adds that the omission of the serial comma "often leaves readers helpless against ambiguity."