Bacgh means: An even more powerful version of the Scottish Omnipurpose Exclamation “Ach” followed usually by a complaint 1 and expressions of extreme hardcoredness2. As many extra letters and syllables as necessary, or as amusingly as possible. It is used in order to avoid it being referred to as “Bach” when it is written. This spelling is also different than the classical musician who is not at all Scottish. (in Community Dictionary, added by Riley Briggs)