noun, noun which may take the genitive case particle 'no'
anti-establishment side; anti-government faction
Refers to the group or side opposing the current political or social establishment. Often used in news or political commentary.
See also: 反体制 (はんたいせい)
The anti-establishment demonstrators gathered in the square.
He spoke from the anti-government side.
反体制 is the abstract concept of being anti-establishment, while 反体制側 specifically refers to the side or group that holds that stance.
Compound of 反 (anti-) + 体制 (establishment/system) + 側 (side).