Definition of demy in English:


(also metric demy)


  • 1A paper size, now standardized at 564 × 444 mm.

    • ‘All books are in metric Demy format unless otherwise stated.’
    1. 1.1 A book size, now standardized at 216 × 138 mm.
      • ‘There are many standard formats – Metric Demy Octavo (216 x 138. mm) or Metric Crown Octavo (186 x 123 mm) are common ones.’
      • ‘In any press, the most frequently used sizes of pages are demy quarto (1/4), demy octavo (1/8), crown quarto and crown octavo.’
    2. 1.2 A book size, now standardized at 276 × 219 mm.
      • ‘The book is very nicely got up by the publisher in format metric demy 4to (280 mm × 216 mm; 11 in × 8.5 in) and expertly set by the author.’
      • ‘Reg, Following Pat's email, I think the old Hansard sizes were demy quarto but I could be mistaken.’


Late Middle English (as an adjective in the sense half-sized): from demi-, or from its source, French demi half.