- Alternative form of battleline.
(plural battle lines)
- (military, army) The notional line on either side of which opposing forces are arrayed, and at which they meet in battle; a fortified line, short of the line where battle is expected, and behind which forces are arrayed; a forward line of infantry or other force, prepared for battle.
- (military, navy) A line of battle.
- (figuratively, usually plural) Any of those parts of a contest which, as a result of strategic decisions on both sides, are most closely fought and will likely determine the contest's course and outcome.