An unspecified or unspecifiable object; something one does not know the name of or does not wish to name; gadget, gizmo (1980s+ Computer)
/frob'nits/, plural "frobnitzem" /frob'nit-zm/ or "frobni" /frob'ni:/ (TMRC) An unspecified physical object, a widget. Also refers to electronic black boxes. This rare form is usually abbreviated to "frotz", or more commonly to frob. Also used are "frobnule" (/frob'n[y]ool/) and "frobule" (/frob'yool/). Starting perhaps in 1979, "frobozz" /fr*-boz'/ (plural: "frobbotzim" /fr*-bot'zm/) has also become very popular, largely through its exposure as a name via Zork. These variants can also be applied to nonphysical objects, such as data structures.
Pete Samson, compiler of the original TMRC lexicon, adds,q "Under the TMRC (railway) layout were many storage boxes, managed (in 1958) by David R. Sawyer. Several had fanciful designations written on them, such as "Frobnitz Coil Oil". Perhaps DRS intended Frobnitz to be a proper name, but the name was quickly taken for the thing". This was almost certainly the origin of the term.