(physics) A spectrum, typically produced by a luminous gas, that consists of separate lines typical of particular elements

A permanent wrinkle on the forehead.

plural of worry line

(anatomy) An imaginary line drawn through the acanthion and the auditory meatus.

plural of acanthiomeatal line

(US) To skip to the head of a queue without waiting for one's turn.

Misspelling of toe the line.

plural of fine line

plural of tram line

Alternative spelling of tramline