left wing

noun

1. members of a liberal or radical political party, or those favoring extensive political reform.
2. such a party or a group of such parties.
3. the part of a political or social organization advocating a liberal or radical position.

noun

1. (often capital) the leftist faction of an assembly, party, group, etc; the radical or progressive wing
2. the units of an army situated on the left of a battle position
3. sport
   1. the left-hand side of the field of play from the point of view of either team facing its opponents’ goal
   2. a player positioned in this area in certain games

adjective left-wing

4. of, belonging to, or relating to the political left wing

n.also (as an adjective) left-wing, 1871 in the political sense (1530s in a military formation sense), from left (adj.) + wing (n.). Related: Left-winger. The liberal or radical faction of a political group, as in Many consider him a leader of the Democratic Party’s left wing. This expression originated in the seating practice of European legislatures, whereby those holding liberal views were assigned to the left side of the house. [First half of 1800s]