adj

• (ice hockey) Occurring during or as a result of a breakaway (see Noun)
  "2016, Scott Feschuk, "Counting down the most annoying in video review, by sport," sportsnet.ca, 10 July, 2016, http://www.sportsnet.ca/baseball/mlb/counting-annoying-video-review-sport/ In a league starved for scoring, the challenge ensures that some super-sweet breakaway goals will be overturned because a dude was three microns offside."
• (entertainment industry) Enjoying rapid popular success.
  "The New York quintet call themselves Dr. Buzzard's Original Savannah Band, and their RCA debut LP is this season's breakaway disco act."

noun

• (cycle racing) A group of riders which has gone ahead of the peloton.
  "The summit of the climb came 38km from the end of stage 14, which began in Limoux and ended in Foix in the foothills of the Pyrenees, and the incident occurred as the peloton emerged into the light and passed under the banner at the top, a quarter of an hour behind a five-man breakaway."
• (ice hockey) A situation in the game where one or more players of a team attack towards the goal of the other team without having any defenders in front of them.
  "2015, Eric MacKenzie, "Canucks fall 2-1 to Oilers in OT," vancouver24hrs.ca, 18 October, 2015, https://web.archive.org/web/20151020145050/http://vancouver.24hrs.ca/2015/10/19/canucks-fall-2-1-to-oilers-in-ot With the game tied 1-1 early in the third, Henrik got free on a breakaway and was stopped by Oilers goalie Anders Nilsson […]"
• (boxing) The act of getting away from one's opponent; the separation of the boxers after a spell of infighting.
  "2011, Colleen Aycock and Mark Scott (eds.), The First Black Boxing Champions: Essays on Fighters of the 1800s to the 1920s, Jefferson, NC: McFarland & Co., Appendix: The Great Fights, George Dixon vs. Jack Skelly (September 6, 1892), p. 262, The gong sounded almost immediately after the breakaway."
• (Australia) A stampede of animals.