Meaning of DOUBLE in English
( a. )
To make of two thicknesses or folds by turning or bending together in the middle; to fold one part upon another part of; as, to double the leaf of a book, and the like; to clinch, as the fist; -- often followed by up; as, to double up a sheet of paper or cloth.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012