Definition of "subreddit"

They wanted to give voice to their feeling, in one moderator’s words, that the company’s bosses ‘‘do not respect the work that is put in by the thousands of unpaid volunteers who maintain the communities of the 9,656 active subreddits,’’ as the individual forums are called.

2015 July 21, Adrian Chen, “When the Internet’s ‘Moderators’ Are Anything But”, in New York Times‎

We measure the similarity between entire subreddits both in terms of user similarity and topical similarity.

2015, Jack Hessel, Alexandra Schofield, Lillian Lee, David Mimno, “What do Democrats do in their Spare Time? Latent Interest Detection in Multi-Community Networks”, in arXiv‎