Definitions
1.nounA cap, usually brightly coloured with bells and tassels, as worn by a court jester or fool.
2.noun(strictly) Writing paper sheets measuring 13.25 x 16.5 inches
3.noun(more usually) Such a sheet folded or cut in half, thus approximately 8 x 13.25 inches.
4.nounPrinting paper measuring 13.5 inches x 17 inches.