What is the meaning of Mainstream?

Used or accepted broadly rather than by small portions of a population or market.

The principal current in a flow, such as a river or flow of air

That which is common; the norm.

To popularize, to normalize, to render mainstream.

To become mainstream.

To educate (a disabled student) together with non-disabled students.

mainstream (the dominant way of thinking or the most popular form of action)

mainstream jazz

mainstream

Source: wiktionary.org