[perverted from mathematical jargon]
adj. An expression used ironically to characterize unquantifiable behavior that differs from expected or required behavior. For example, suppose a newly created program came up with a correct full-screen display, and one publicly exclaimed: "It works!" Then, if the program dumps core on the first mouse click, one might add: "Well, for suitably small values of 'works'."
Compare the characterization of pi under random numbers.