[late L. suppedāneum, neut. sing. used subst. of suppedāneus, SUB- 1 a + ped-, pēs foot.] A support for the feet of a crucified person, projecting from the vertical shaft of the cross.
1863. Lady Eastlake, in Mrs. Jameson, Hist. Our Lord, II. 142. His feet always separate, and with two nails upon the foot board, or suppedaneum (a Greek feature).
1887. J. R. Allen, Early Chr. Symbol., 155. In some cases the feet of the Saviour are supported on a suppedaneum.