mess-dos /mes-dos/ n. Derisory term for MS-DOS. Often followed by the ritual banishing "Just say No!" See MS-DOS. Most hackers (even many MS-DOS hackers) loathe MS-DOS for its single-tasking nature, its limits on application size, its nasty primitive interface, and its ties to IBMness (see {fear andloathing} ). Also `mess-loss', `messy-dos', `mess-dog', `mess-dross', `mush-dos', and various combinations thereof. In Ireland and the U.K. it is even sometimes called `Domestos' after a brand of toilet cleanser.