I have seen the term 'monospace' at dozen of places. Can you tell me what does monospace font mean and what monospace fonts are available in Python and Tkinter?
"Monospace" just means that all characters take the same, fixed width for each character.
The converse is a "proportional" font where narrower letters e.g i take less space and wider letters e.g. m take more space.
Which ones are available depend on what you have installed.