Die, as in He turned up his toes last week. This expression alludes to the position of the toes when one lies flat on one's back without moving. It may be obsolescent. [Mid-1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.