The way in which a society, on both a large and a small scale, oppresses and discriminates against people who have, or are perceived to have, physical, cognitive, or other disabilities. Disabled people coined this word to mirror the form and meaning of existing words like racism and sexism.
Ableism can take the form of anything from the prejudice that casts individual disabled people as tragic and childlike objects of pity, to the systems in society which exclude large numbers of disabled people from gainful employment or a decent standard of living. The word can be used to describe both negative and seemingly positive stereotypes. It can include both abstract ideas and concrete architectural barriers.
Ableist is the adjective form. Other words for the same concept include
disableism and disabilism.