ambulatory vs on wheels

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 wheels

prep
  • Used other than figuratively or idiomatically: see on, wheels. (Having wheels affixed to the bottom, and so transportable; synonym of wheeled). 

  • Mobile; able to be moved; especially, synonym of on the move. 

  • To a large degree, excessively. 

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