(ecology) A theory involving natural selection based on quantity.

Censored spelling of wanker.

(nautical) Initialism of research vessel;

(computing) Alternative form of ER; Initialism of entity-relationship.

Alternative form of ER

(fandom slang) The ship of characters Ron Weasley and Hermione Granger of the Harry Potter series.

(fandom slang) The ship of characters Ron Weasley and Hermione Granger of the Harry Potter series.

(typography) The usual form of the letter r (which is r), as contrasted with r rotunda (ꝛ).

(US, film) a movie that is definitely, or most likely will be, R-rated ("Under 17 requires accompanying parent or adult guardian.") by the Motion Picture Association (MPA), typically due to having multiple scenes of violence or nudity.

(logistics, supply chain management, retail) Initialism of forecasting and replenishment.