goal line

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Sports A line located at either end and typically running the width of a playing area, on which a goal is positioned.
• noun Football A line at either end of the playing field over which the ball must be carried or passed to a receiver to score a touchdown.

from The Century Dictionary.

• noun In foot-ball, hockey, lacrosse, and similar games, a line at the end of the field which passes through the goals.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Sport) The line bounding the end of a playing field, at or directly in front of the goal{3}.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun soccer, Gaelic football the boundary of the field that runs along its width at each end, and across the front of the goal.
• noun American football part of a vertical plane separating an end zone from the field of play when the ball is touched or is in player possession. The plane extends beyond the sidelines. A team’s goal line is that which it is defending.
• noun ice hockey the red line that runs across the rink and the front of the goal.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a line marking each end of the playing field or pitch; where the goals stand