mainstream

adj

1. Used or accepted broadly rather than by small portions of population, market, scientific community, etc.

   “They often carry stories you won't find in the mainstream media.”

   “As unsubstantiated claims receive significant backing, skeptics and defenders of mainstream science enter the fray.”

   “The mainstream media hones in on bad news stories where UK railways are concerned, yet gives scant attention to the many items of good news emerging from the network.”

   “If Ms. Le Pen looks more mainstream now, it’s because the mainstream looks more like her.”

noun

1. The principal current in a flow, such as a river or flow of air
2. (usually)That which is common; the norm.

   “ideas outside of the mainstream”

   “George Herbert Walker Bush of Phillips Andover Academy and Yale University proclaimed in the first Presidential candidates' debate that he was “in touch with the mainstream of America.””

   “Long content with being the BMW of the computer industry, suppying finely crafted machines to a relatively small number of fanatic customers, Apple now wants to become a Ford or Toyota, to move into the mainstream.”

   “"Railways seldom slavishly followed styles to be seen in the mainstream of contemporary architecture," HE [Historic England] explains.”

verb

1. (transitive)To popularize, to normalize, to render mainstream.

   “Just as the gang peace movement desired to mainstream hardcore bangers into civic society, The Chronic wanted to drive hardcore rap into the popstream.”

   “Acknowledging the role X plays in mainstreaming the worst constituencies makes for awkward conversations with those who continue to use it.”

2. (intransitive)To become mainstream.

   “In a nonchurch context, we can look more explicitly at formerly New Age practices to see if and how they have mainstreamed.”

3. (US, transitive)To educate (a disabled student) together with non-disabled students.

   “Despite these beliefs, the decision to send my son to a regular school was not made easily. I didn't know of any child as disabled as he who had been mainstreamed.”