duodecimo
/ˌduːoʊˈdɛsɪmoʊ/
noun
- A book size that is about 5 by 7.5 inches (12.7 by 19 cm), made by folding a sheet of paper into twelve leaves.
- Many 18th-century novels were printed in duodecimo format to keep costs low.
- The small duodecimo edition of the novel fit easily into her coat pocket.
- The library's rare book collection includes several duodecimo volumes from the 1700s.