Wiktionary
n. The prevailing vernacular culture in any given society, including art, cooking, clothing/fashion, entertainment, fads, films, mass media, music, sports (,) and style
Wikipedia
Popular culture or pop culture is the entirety of ideas, perspectives, attitudes, images, and other phenomena that are within the mainstream of a given culture, especially Western culture of the early to mid 20th century and the emerging global mainstream of the late 20th and early 21st century. Heavily influenced by mass media, this collection of ideas permeates the everyday lives of the society. The most common pop culture categories are: entertainment (movies, music, TV), sports, news (as in people/places in news), politics, fashion/clothes, technology, and slang. Popular culture has a way of influencing an individual's attitudes towards certain topics.
Popular culture is often viewed as being trivial and " dumbed down" in order to find consensual acceptance throughout the mainstream. As a result, it comes under heavy criticism from various non-mainstream sources (most notably religious groups and countercultural groups) which deem it superficial, consumerist, sensationalist, and/or corrupt.