There is no such thing as "suppresing" an event. You can stop propagation of an event, and prevent the default action of an event, but supressing an event is not a thing.
Do read:
http://leafletjs.com/reference-1.0.3.html#domevent-stoppropagation
http://leafletjs.com/reference-1.0.3.html#domevent-preventdefault
http://leafletjs.com/reference-1.0.3.html#domevent-stop
https://developer.mozilla.org/en-US/docs/Web/API/Event/stopPropagation
https://developer.mozilla.org/en-US/docs/Web/API/Event/preventDefault
event.preventDefault() vs. return false
Do you want to stop the event from bubbling? Do you want to prevent the browser from displaying the right-click menu? Both?
Also note that jQuery events are not DOM events, and furthermore, Leaflet events are not DOM events. Stopping a jQuery/Leaflet event might not stop the underlying DOM event under some circumstances. Using Vanilla JS or some super-simple wrapper as L.DomEvent.on()
helps to regain control in these cases.