the ideas, attitudes, or activities that are shared by most people and regarded as normal or conventional:they withdrew from the mainstream of European politics
(also mainstream jazz) [mass noun] jazz that is neither traditional nor modern, based on the 1930s swing style and consisting especially of solo improvisation on chord sequences:it was a form of jazz that had strayed away from the mainstream
adjective
belonging to or characteristic of the mainstream:mainstream pop music
(of a school or class) for pupils without special needs:children with minor handicaps would be able to attend mainstream schools
verb
[with object]
bring into the mainstream:vegetarianism has been mainstreamed
mainstream in other Oxford dictionaries
Definition of mainstream in the US English dictionary