Dear Geist,
Are the words repetitious and repetitive interchangeable? The Canadian Oxford Dictionary defines repetitious as “characterized by repetition, esp. when unnecessary or tiresome.” The next word is repetitive, which is defined as “= repetitious.” Why do we have two words that are so similar and mean exactly the same thing?
—Just Wondering, Dawson Creek BC
Dear Wondering,
Language being what it is, the answer depends on which guide you consult—and maybe what country you live in. Yes, Canadian Oxford says they are interchangeable, and does not mention the non-tiresome uses of repetitive, such as repetitive strain injury. The Oxford Guide to Canadian English Usage makes no mention of either word. Garner’s Modern American Usage (2009) says that the two words are “undergoing differentiation”: repetitive referring to “repeating,” and repetitious to “repeating in an annoying way.” Fowler’s Modern English Usage (UK; rev. 3rd edition, 1998) says much the same thing and reminds us that in the late 1800s, there were four—count ’em, four! —similar words in use: repetitive and repetitious, and also repetitional and repetitionary. Yikes!
— The Editors