Rebound - redound

The verbs 'to rebound' and 'to redound' are two words which can be confused - there is only one letter of difference, and the contexts in which they are used are similar. This confusion has been long-standing. The OED etymologies include, for rebound: "In ME. and early mod.E. freq. confused with REDOUND v.; see 1b-1d and 3c", and, for redound: "in 4 and 5 there is probably some confusion with REBOUND v." It appears that there is a widespread carelessness in distinguishing between the two, even in academic writing. The two words now appear inextricably confused.

The best explanation AWE can find of a very subtle distinction is in the Longman Guide to English Usage, which says:

To rebound is to spring back, like a ball or an echo: Their hatred rebounds on themselves. Redound means 'to contribute to' (Your behaviour will redound to your credit), but it also means 'become reflected on', a sense which is close to rebound but should be distinguished from it: The President's action redounds on his party.

AWE might add to a confusion that is widespread this advice: that, in general, 'rebound' may be applied to an unintended (but bad) consequence; 'redound' may be more positive. But our best advice is to avoid both words. You can nearly always replace 'rebound' by 'came back' or 'returned', or, to be more vivid, even 'bounced [back]' or 'ricocheted', so you do not need to use it (unless you are a sports scientist or physicist, for example, and want to use rebound literally). The one phrase which, being nearly a cliche, you may not want to avoid, is "redounded to his credit": don't say "rebounded to his credit".

Rebound is also a noun, most often seen outside sports contexts perhaps in the phrase 'on the rebound', used, rather dismissively, of a romantic relationship contracted after a disappointing previous relationship. A lover 'caught on the rebound' (the image is from cricket) tends to be seen as ipso facto second best. (OED only records a noun 'redound' as obsolete.)

The etymologies are not simple, and are themselves confused and confusing. OED has, for rebound, v.:

"[< Middle French rebondir to resound, ring out (c1150 in Old French), to cause (something) to bounce back (c1393), (reflexive) to come forward (1480; French rebondir) < re- RE- prefix + bondir BOUND v.2 In Middle English and early modern English frequently confused with REDOUND v.; compare senses 1a , 1b , 2a , 2b, and also discussion at REDOUND v. In early use frequently used to translate classical Latin redundāre REDOUND v.; compare senses 1a , 2a , 3a.]",

and for redound, v.:

"< Anglo-Norman redounder, Anglo-Norman and Middle French redonder, redunder (French (now rare and literary) rédonder) to be plentiful, abound (first quarter of the 13th cent. in Old French), (of a bodily fluid) to overflow (1314), to have the effect of contributing to some advantage or disadvantage to (a person) (late 14th cent. in redonder à, redonder en, early 15th cent. in redonder sur), to proceed, arise from something (early 15th cent. in redonder de), in Anglo-Norman also to resound, re-echo (second half of the 13th cent. or earlier), to rebound (end of the 13th cent. or earlier), to return, to come back (early 14th cent. or earlier) and its etymon classical Latin redundāre to flow back, to overflow, to spread over, to turn (to one's profit, loss, etc.), to recoil (upon), to be present to excess, to abound (in) < red-, variant (before a vowel) of re- RE- prefix + undāre to flow in waves (see UNDATION n.). Compare Catalan redundar (15th cent.), Spanish redundar (late 14th cent.), Portuguese redundar (1587), Italian ridondare (a1306; also †redondare, †redundare), all earliest in sense 2a.

... In the obsolete uses the precise sense is not always clear; in senses 3 and 5 there is probably some confusion with REBOUND v. (see discussion at that entry).

Französisches etymol. Wörterbuch at redundare suggests that the French word in the sense 'to rebound' and related senses may show a different, ultimately imitative, origin.]

You may also want to see AWE's page on bound.