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

Altuve’s latest landed inside the left-field foul line, breathing life into a ballpark silenced for so much of this seismic series. —Chandler Rome, New York Times, 22 Sep. 2025

But Gray answered with a 3-pointer on the next possession, and Wilson knocked down a jumper from the foul line to push Las Vegas back in front for good. —Grant Afseth, MSNBC Newsweek, 26 Aug. 2025

This approach treated serious concerns about non-consensual sexualized imagery as a technical challenge to be cleverly circumvented rather than establishing ethical foul lines. —Douglas B. Laney, Forbes.com, 17 Aug. 2025

So Dylan Cease, Nestor Cortes, Yu Darvish, Michael King, Joe Musgrove and Nick Pivetta followed Vásquez out of the bullpen and walked along the right-field foul line to Dodger Stadium’s visiting dugout as Vásquez jogged to the mound for his second-inning entrance. —Jeff Sanders, San Diego Union-Tribune, 16 Aug. 2025

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
• byline
• canine

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)