to unfold; render single.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use undouble in a sentence
To undouble him, that he might fit into a coffin, they had been forced to lug him to a fire and thaw him out a bit.The Spinner's Book of Fiction | Various
His gum boots screeched, the bench creaked as he began to undouble himself.First Fam'lies of the Sierras | Joaquin Miller
The rheumatiz stiffened me so I couldn't double up, and now it has stiffened me so I can't undouble.Giles Corey, Yeoman | Mary E. Wilkins Freeman