co·pa·cet·ic or co·pa·set·ic (kō'pə-sět'ĭk) adj. Very satisfactory or acceptable; fine: "You had to be a good judge of what a man was like, and the English was copacetic"(John O'Hara).
[Origin unknown.]
co·pa·set·ic (kō'pə-sět'ĭk) adj. Variant of copacetic.