MEME  [noun]

1. a cultural item that is transmitted by repetition and replication in a manner analogous to the biological transmission of genes.

2. a cultural item in the form of an image, video, phrase, etc., that is spread via the Internet and often altered in a creative or humorous way.

Etymology: 1976, introduced by evolutionary biologist Richard Dawkins in “The Selfish Gene,” coined by him from Greek sources, e.g. mimeisthai, “to imitate” (see mime), and intended to echo gene.