this is by no means (I'm sure) the last word on the subject, but here's what The Word Detective had to say back in 2005:

In any case, if your dictionary doesn't list "discombobulate," you definitely need a new dictionary†. However, your search for "combobulate" will come up dry in even the best dictionary, because "combobulate" by itself isn't a word. "Discombobulate," meaning "to throw into a state of confusion, to disturb or disorient," is an invented word apparently formed as a joking alteration of "discompose" or "discomfit," both slightly musty terms for confusing or upsetting a person. "Discombobulate" first appeared around 1834.

† - heh. I often used the word 'smegma' as the criterion for this.

Last edited by tsuwm; 02/08/11 09:20 PM.