purism (n.)

A term used pejoratively in LINGUISTICS to characterize a school of thought which sees a LANGUAGE as needing preservation from the external processes which might infiltrate it and thus make it change, e.g. the pressures exercised by other DIALECTS and languages (as in LOAN WORDS) and the variations introduced by colloquial speech. This purist concern is considered misplaced by linguists, who point to the inevitability of language change, as a reflex of social, cultural and psychological development.