term taken from baseball, referring initally to the brief summary or outline of a film used by a writer to sell the idea to a decision-maker or by a distributor to sell it to the public. The one-line pitch is a summary of the work's action in a single phrase. It is an excellent aid to writing as it acts as an overall guideline. (Lavandier, 2005)
a concise verbal and sometimes visual presentation of an idea for a film or television series. (Becomes visual by including storyboard art, research materials and images.) (Griffiths, 2015)
a brief verbal description of a screenplay idea or script (often based on a written logline) usually told by a writer, director, or producer to someone who is interested in buying, financing, or developing a story idea or script. (Austin Community College, 2014)