foul line

noun

1

: either of two straight lines extending from the rear corner of home plate through the outer corners of first and third base respectively and prolonged to the boundary of a baseball field

2

: a line across a bowling alley that a player must not step over when delivering the ball

3

: either of two lines on a basketball court parallel to and 15 feet from the backboards behind which a player must stand while shooting a free throw

Examples of foul line in a Sentence

The ball landed just inside the right-field foul line.

Recent Examples on the Web

In the fifth inning, left fielder Bella Perez made a diving catch near the foul line on a drive by Mater Dei slugger Tulutululelei Salue. —Dan Albano, Oc Register, 2 June 2026

Carlos Beltran, back at Citi Field for the first time since the Mets traded him last July, hit a line drive over third base in the sixth inning that hit the foul line and should have been called fair. —Assistant Sports Editor, Los Angeles Times, 1 June 2026

Rice swung at the first pitch from left-hander Noah Cameron, a four-seam fastball, to hit a triple that took an awkward bounce off the left field wall and scattered away from Royals left fielder Isaac Collins past the foul line. —Pj Green, Kansas City Star, 28 May 2026

The Swedish guard also shot 49.6% from the field, 32.3% from three-point range and 79.7% from the foul line this season. —Anthony Chiang, Miami Herald, 26 May 2026

Word History

First Known Use

1868, in the meaning defined at sense 1

Rhymes for foul line

• affine
• airline
• align
• aline
• assign
• baseline
• beamline
• benign
• bloodline
• bovine
• brucine
• byline

Kids Definition

foul line

noun

1

: either of two straight lines running from the rear corner of home plate through first and third base on to the boundary of a baseball field

2

: a line across which a player must not step (as when bowling or shooting a free throw)