Boobalang is a generic word that can stand in for any other noun in a sentence. It is commonly used to replace a word that has momentarily eluded one due to a failure of memory. It is, in many ways, a companion word to linkmy and serves the same purpose, to whit that of a metasyntactic variable.
Oy Gazric, have you moved my..um.. boobalang? It was on my linkmy and now I can't find it.