In contemporary media language, an increasingly frequent phenomenon is the misapplication of the word term when what is meant is phrase. This was exemplified in full by a discussion this morning on the NPR program Morning Edition that explored how Americans of a certain age wish to refer to themselves (as well as hear themselves referred to). In assessing phrases like older adult and senior citizen, the discussants mistakenly kept using the word term instead of phrase.
This error evidently derives from the mindless transference of the plurale tantum terms––as in phrases like on good terms with, terms of an agreement, etc.––to the designation of the singular term, where the latter, strictly speaking, consists of a single word and not more than one. Lamentably, this error has now been legitimated as standard usage in dictionaries, as reflected, for example, in the following definition: ‘a word or group of words designating something, especially in a particular field, as atom in physics, quietism in theology, adze in carpentry, or district leader [sic!] in politics’ (Dictionary.com).
The historical process exemplified by what started as an error needs to be taken account of in describing the range of factors underlying linguistic change. All living languages, wherever they are spoken, inevitably include examples that owe their origins to failures of thought and other species of misinterpretation but become canonized over time as correct by speakers who have either lost the feeling of their erroneousness or been born at a stage of the language when the transition is largely complete.