conforming or adhering to what is regarded as orthodox liberal opinion on matters of sexuality, race, etc.: usually used disparagingly to connote dogmatism, excessive sensitivity to minority causes, etc.
See politically correct in American Heritage Dictionary 4
adjective Abbr. PC
Of, relating to, or supporting broad social, political, and educational change, especially to redress historical injustices in matters such as race, class, gender, and sexual orientation.
Being or perceived as being overconcerned with such change, often to the exclusion of other matters.