1969, Kenneth Macpherson, Close up: Volume 10:Shown with the foregoing, the desperate and blastworthy Puss in Boots
1996, Arthur Roy Eckardt, On the way to death: essays toward a comic vision:Oxford Universal Dictionary is more accepting of things blastworthy. It allows places for both " — " and "flatulence," although respecting the former it does confess "not in decent use."
(figuratively) Indicative of an exceptionally good time; enjoyable.Last year we had a blast; this year will be even more blastworthy.
