tramline

noun

1. The rails that a tram runs on.
2. (British)Either of the two pairs of sidelines marked on a tennis court which mark the outside of the singles and doubles playing areas.
3. A scratch on a film, usually vertical, that extends through multiple frames.

   “The tramline is therefore much less obvious on the screen. Also, if the scratch is on the base (i.e., on the back of the film), then it will not be in sharp focus.”

4. A mark or bruise having the shape of two parallel lines.

   “a tramline scar”

   “The well-reported "tramlines" or parallel punctate scars on either side of the vein were seen in only four patients.”

5. A pair of vertical bars (||) placed to the left of the headword in certain editions of the OED to indicate that the term is "alien or not fully naturalized" (such as a recent borrowing).

verb

1. (intransitive)Of a vehicle: to tend to follow the contours of the ground with its wheels.