(engineering) A line which serves as a reference or base for the measurement of other quantities.

(nautical) A ceremony performed on board ship when members of the crew or passengers cross the equator for the first time.

present participle of cross the line

(management) Any primary business function that would affect customers or profits if interrupted

(idiomatic) A difference, albeit vague and difficult to discern.

Reactionary or conservative. / Long-established.

Alternative spelling of breadline

(meteorology) A line of thunderstorms, hundreds of miles long, with squalls at the advancing edge

plural of punch line

(geology) the line that marks the interface between land and water; a shoreline; it changes daily, and over geologic time