What I can say, generally speaking though, is there is not one definition of disability. Most folks use the UN definition of disability, which is those who have long-term physical, mental, intellectual, or sensory impairments, which in interaction with various barriers may hinder their full and effective participation in society on an equal basis.
What has happened is in the past it moved from more of a medical definition of disability to more of a societal one, and disability now is broader in the sense that a person can think of themselves as disabled as to the barriers that they have to face in employment or inclusion in other spheres of their daily activities. For different programs, whether they be federal, provincial or municipal, there are different criteria, so different definitions of disability.
The short answer is no, there is not one definition for disability.