shoetree

[shoo-tree] /ˈʃuˌtri/
noun
1.
one of a pair of foot-shaped devices, usually of metal or wood, for placing in a shoe to maintain its shape when it is not being worn.
Origin
1820-30; shoe + tree
British Dictionary definitions for shoetree

shoetree

/ˈʃuːˌtriː/
noun
1.
a wooden or metal form inserted into a shoe or boot to stretch it or preserve its shape