touchline
Synonym discussion
Sense: noun/1
Touchline is the usual British term for the long side boundary of a soccer or rugby field. Sideline often means the same thing, but it is more common in American English and can also mean the area where coaches and substitutes stand. Boundary line is a broader technical label for any marked edge of a playing area, so it does not sound as sport-specific as touchline. Goal line is different because it is the short line at either end near the goal. Byline is narrower still, usually meaning the part of the line near the attacking end in soccer. A winger may race down the touchline, but a shot crosses the goal line.
Common collocations
Etymology
Touchline is a modern English compound formed from touch and line. In British field sports, touch came to mean the area outside the side edge of the field, so touchline named the marked boundary that sends the ball or a player into touch when it is crossed. The first part came into English through Old French from a Vulgar Latin verb meaning to strike or make contact, and the second part came through Old French from Latin linea, meaning a line or thread.
First known use
1863
1863, in the meaning defined above