Type of service fault in which a player, during the serve, steps on or over the baseline into the court before striking the ball. A foot fault may also occur if the player steps on or across the center hash mark and its imaginary perpendicular extension from the baseline to the net. Found on http://en.wikipedia.org/wiki/Glossary_of_tennis_terms
when a player, during the serve, steps on or over the baseline into the court before striking the ball, which results in a service fault. A foot fault may also occur when the player steps on or across the center hash mark and its imaginary perpendicular extension from the baseline to the net Found on http://www.translationdirectory.com/glossaries/glossary148.htm
When the rear foot is not completely on or above the mat at the moment of delivery. The player could incur a penalty. Found on https://www.bowls.co.uk/glossary
Where the server puts his foot onto or over the Baseline before hitting the ball. If performed on a 1st serve, you will only have your 2nd serve remaining. If performed on your 2nd serve you lose the point. Found on https://www.encyclo.co.uk/local/22355
a fault consisting in the failure of the server to keep both feet behind the base line until the ball is hit or to keep at least one foot on the ground while hitting the ball. Found on https://www.infoplease.com/dictionary/foot-fault