adjective

1. coming after, and usually in reaction to, modernism in the 20th century, esp. in the arts and literature; specif., of or relating to a diffuse cultural and artistic trend or movement, esp. in art, architecture, and writing, since the 1950s, characterized by eclecticism in style and content, freedom from strict theoretical constraints, indifference to social concerns, etc.
2. designating or of various theories used widely in criticism and interpretation, which question or reject claims of absolute certainty, objective truth, and, as in language or works of art, intrinsic meaning, regarding such claims instead as assertions of privilege, political power, etc.