lane n. an area of expertise or (military) responsibility; a mandate. Etymological Note: As explained in the comments, this usage is probably an extension of the idea of a shooting lane, where each shooter must keep fire within a long track. Perhaps reinforced by lanes on a highway or running track, or by a lane as a path, meaning “a course of action or conduct.” (source: Double-Tongued Dictionary)
Further reading
The archaic English word ruelle means “the space between a bed and the wall.” It’s adapted from French ruelle meaning “a small alley or lane.” This is part of a complete episode.
Related
Cat hair may be something you brush off, but cat hair is also a slang term that means “money.” In the same way, cat beer isn’t alcoholic — some people use cat beer as a joking term for “milk.” And imagine walking on a...
Antonyms: The “big picture”; the mission of the command as a whole. While the original source is probably “athletic” (specifically bowling), the military use of “lane” is peculiar to the firing range. Each soldier shooting has a “lane” running from his or her position to the most distant target for which he or she is responsible. The pattern, from above, looks like a bowling alley. Many of us remember the word “lane” in this context from one of the last commands in a cycle of firing: “Alibi firers, watch your lanes!” (Alibi firers are those who had a weapon jam or otherwise had some reason for not shooting all of their rounds during shooting for record.) In the U.S. Army, the term “lane” extends to other training contexts where individual soldiers or units train side-by-side, such as squad maneuvers. The key meaning in all of these applications is that the soldier or unit training must not stray outside the assigned lane into a lane assigned to another soldier or unit. It is a control measure, to avoid confusion or worse (if live ammunition is being used). The expression “watch your lane” was subsequently used to counsel soldiers to pay attention to their own responsibilities and not get involved in responsibilities assigned to others.
Excellent commentary. I will revise the entry reflect it.