'Sherry' is an English mangling of 'Xeres/Jerez' — the Spanish city, back-formed from 'sherris.'
A fortified wine produced in the 'Sherry Triangle' near the city of Jerez de la Frontera in southwestern Spain.
An English corruption of 'Xeres' (the older Spanish spelling of 'Jerez'), the Andalusian city where the wine is produced. The full name was 'Jerez de la Frontera' (Jerez of the frontier — referring to the medieval frontier between Christian and Moorish Spain). 'Jerez' itself derives from Arabic 'Sherīsh' (شريش), which in turn adapted
Shakespeare called it 'sherris-sack' — 'sack' from Spanish 'saca' (to draw out, i.e., to export). In Henry IV Part 2, Falstaff delivers a famous soliloquy praising 'sherris-sack' for warming the blood and sharpening wit. The English treated 'sherris' as a plural and back-formed the singular 'sherry' — a false depluralization, the same process that created 'pea' from 'pease' and 'cherry' from 'cherise.'