noun phrase. An affliction of the undernasties that is too terrible or titillating to behold.
Real citation: "An homage to, or rip-off of, Art Frahm’s pinups of the 1940’s, in this scene our fair maiden has experienced a catastrophic underwear failure. 'Whoops!' she declares, as her failure is made plain to see. Should have fixed that waist band a little tighter…"
(Sept. 1, 2005, Flickr, http://flickr.com/photos/dklo/39408496/)
Made-up citation: "I used to suffer from catastrophic underwear failure. Now I don no less than six pairs of underthings, underthongs, nethergarments, and underoos before getting up in the morning. I like to feel safe."