"piece of cloth used to mend another material," late 14c., of obscure origin, perhaps a variant of pece, pieche, from O.N.Fr. pieche (see piece), or from an unrecorded O.E. word. The verb is mid-15c., from the noun; electronics sense of "to connect temporarily" is attested from 1923. Phrase not a patch on "nowhere near as good as" is from 1860.
"fool, clown," 1549, perhaps from It. pazzo "fool," which is possibly from O.H.G. barzjan "to rave." Form perhaps infl. by folk-etymology from patch (1), on notion of a fool's patched garb.