A Quick and Simple Dictionary

sidetrack

1. Noun.  (rail transport) A second, relatively short length of track just to the side of a railroad track, joined to the main track by switches at one or both ends, used either for unloading freight, or to allow two trains on a same track to meet (opposite directions) or pass (same direction); a railroad siding.
2. Noun.  (sometimes) Any auxiliary railroad track, as ''differentiated'' from a siding, that runs adjacent to the main track.
3. Noun.  (mining) A smaller tunnel or well drilled as an auxiliary off a main tunnel or well.
4. Noun.  An alternate train of thought, issue, topic, or activity, that is a deviation or distraction from the topic at hand or central activity, and secondary or subordinate in importance or effectiveness.
5. Verb.  To divert (a locomotive) on to a lesser used track in order to allow other trains to pass.
6. Verb.  To divert or distract (someone) from a main issue or course of action with an alternate or less relevant topic or activity; or, to use deliberate trickery or sly wordplay when talking to (a person) in order to avoid discussion of a subject.
7. Verb.  To sideline; to push aside; to divert or distract from, reducing (something) to a secondary or subordinate position.
8. Verb.  (intransitive) To deviate briefly from the topic at hand.