Added 9 October 2026 fastball noun Categories: ActionsRare Words noun ! Definition from Wiktionary (CC BY-SA). More about fastball at Wordnik → Where our words come from → A high-speed pitch of a baseball. A four-seam fastball, which is a backspin pitch thrown with a ball gripped in the direction to cause four of the seams of the ball to cross the flight path and released with roughly equal pressure by the index and middle fingers The pitcher had a blazing fastball. verb To throw (something) at a high speed. Origin From fast (adjective) + ball. From Wiktionary, via Kaikki.org (CC BY-SA) Related Words: bullethummerheatersmokeseamfastballerspeedballfastpitchspeedballerfireballerflutterball Back to today's word