Copasetic, also spelled copacetic, copesetic or - less commonly - kopasetic, means very satisfactory or acceptable.
Copasetic is an unusual English language word in that it is one of the few words of seemingly unknown origin that is not considered slang in contemporary usage. It is used almost exclusively in North America, and is said to have been first widely publicized in communications between the astronauts and Mission Control of the Apollo Program in the 1960s.
There are many theories to the origin of copasetic
.It is widely accepted that it originated from some form of American slang. This conclusion stems from the slow introduction of the word into the written language mainly through use in periodicals and in character dialog in 20th century novels. Copasetic may have originated from African American slang in the late 19th century. It was used by African Americans in the American South (most notably by Bill "Bojangles" Robinson) and by jazz musicians in Harlem in the late 19th and early 20th centuries.
David Mamet has written an article about its origins. He suggests that "copasetic" is a contraction of "All is well, for the Cop is on the settee." The American Heritage Dictionary lists alternate spellings that include copasetty and kopasettee, lending some credence to Mamet's theory. Mamet states:
The book that Mamet references might be Gamblers Don't Gamble by Michael MacDougall who, in 1939 (not quite the forty years previous to 1960 that Mamet remembers), provided the same etymology, also tracing its origins to Chicago criminal activity:
Copacetic may be a descendant of the Hebrew phrase "hakol beseder", (literally "all in [the] order" הכל בסדר) meaning "everything is alright", or "Hakol BeTzedek", meaning "everything is justified".
Another theory is that copacetic may have originated from Chinook Jargon, a trade language used in the Pacific Northwest to communicate between tribes, and European traders. The preposition "kopa" is very common in the language, and "Kopasetty" may have been used to mean "doing just fine". This theory was first put forth by Donald L. Martin who stated it derives from the Chinook Jargon word copasenee ("everything is satisfactory").
Yet another theory, put forth by novelist John O'Hara in 1934, claims (without evidence) that the word entered the African American slang lexicon via the Italian of American mobsters. Quoting O'Hara, "I don't know how to spell the Italian, but it's something like copacetti." There is no such word in the Italian language, however.
Dictionary of American Slang entry