A failed attempt at doing something rad.
The K comes from the symbol used for a strike against a batter in baseball.
Also used to mean something very rad, with the K coming from the abbreviation for thousand (a thousand times rad).
The disparity between the two meanings is similar to that of "bad" meaning both good and actually bad.
Originates from BBS days, with overuse leading to confusion and hence the split definition. Only should be used on-line. Meaning should be clear from context.
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