Definition of pied d'éléphant in US English:

pied d'éléphant

(also pied d'elephant)

noun

  • A padded sack used to protect the lower part of the body when sleeping outdoors in a bivouac.

Origin

1950s; earliest use found in Charles Evans (1918–1995), surgeon and mountaineer. From French pied d'éléphant from pied foot + de + éléphant.