I. ˈsīd-ˌtrak noun
Date: 1835
1. : siding 2
2. : a position or condition of secondary importance to which one may be diverted
II. transitive verb
Date: 1880
1. : to shunt aside (as to a railroad siding)
2.
a. : to turn aside from a purpose : deflect
b. : to prevent action on by diversionary tactics
sidetrack an issue