sidetrack

IPA: sˈaɪdtræk

(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.
(sometimes) Any auxiliary railroad track, as differentiated from a siding, that runs adjacent to the main track.
(mining) A smaller tunnel or well drilled as an auxiliary off a main tunnel or well.
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.

(rail transport) To divert (a locomotive or train) on to a lesser used track in order to allow other trains to pass.
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.
To sideline; to push aside; to divert or distract from, reducing (something) to a secondary or subordinate position.
(intransitive) To deviate briefly from the topic at hand.

Examples of "sidetrack" in Sentences

But there's always this kind of sidetrack two that goes on between the first ladies.
It is kind of a sidetrack from the usual Cabinet fare, but might prove interesting to many of you.
It's a sidetrack of an existing well, and the sidetrack is a short sidetrack just to get around the completion.
It was a great "sidetrack" - they learned more in a week and a half of blogging than I could have taught in a month.
I don't think this will 'sidetrack' the discussion - in fact, it relates to a point mentioned in Jason's comment to which I had hoped to return.
The rig has now moved to the Ezzaouia 2 well location to perform the planned sidetrack which is expected to take approximately three to four weeks.
For example, a common practice is to "sidetrack," which means digging an underground offshoot from an existing well to make sure you get as much as you can from a large pocket of oil.
Although the ocean energy bureau plans to conduct the reviews before approving new deep-water wells and other projects that were covered by the moratorium, the government is on track to exempt relatively common "sidetrack"