mobility

1. (now chiefly literary) A tendency to sudden change; mutability, changeableness.countableliteraryuncountable

2. (military) The ability of a military unit to move or be transported to a new position.countableuncountable

3. (chiefly physics) The degree to which particles of a liquid or gas are in movement.countableuncountable

4. (chiefly sociology) The ability of people to move between different social levels or professional occupations.Examples: "The difficulty of rising up the economic ladder is reflected in the decline in mobility in the United States. […] The frustration over the lack of mobility is particularly acute for those without college degrees."countableuncountable