ambulatory vs on foot

ambulatory

adj
  • Of, relating to, or adapted to walking. 

  • Able to walk about and not bedridden. 

  • Performed on or involving an ambulatory patient or an outpatient. 

  • Accustomed to move from place to place; not stationary; movable. 

  • Not yet legally fixed or settled; alterable. 

noun
  • The round walkway encircling the altar in many cathedrals. 

  • Any part of a building intended for walking in; a corridor. 

on foot

prep
  • In progress or in preparation; active, in operation. 

  • On one's feet; walking, jogging or running but not in a vehicle or on the back of an animal. 

How often have the words ambulatory and on foot occurred in a corpus of books? (source: Google Ngram Viewer )