Baretti: A dictionary of the English and Italian languages
Zápp-a, s. f. dim. Zápp-élla, Zápp-éllo, Zápp-étta, Zápp-ettína,Zápp-oncéllo , aug. Zápp-óne,
1. a spade, a mattock; 2. — d'ingegno, (fig.) sharpness of wit. Darsi la — sul piede, to be the cause of one's own misfortunes;3. (mil. t.) an instrument for digging trenches; 4. work done by sappers and miners.
Florio: a worlde of wordes, or most copious, dictionarie in Italian and English
zappa: a Sap, a Mattocke or Pickax to dig, to sap or delue with.