Boyd’s Bible Dictionary:
To wash, a sign of hospitality
(Gen. 18:4; 1 Sam. 25:41; John 13:5-6). To remove shoes, a reverence (Ex. 3:5); sign of mourning (Ezek. 24:17).
Strong’s Dictionary of Greek Words:
Meaning:
from βαίνω (to walk); a pace ("base"), i.e. (by implication) the foot