Plain English Meaning
A path that takes a long way around instead of going straight to where you're going.
Full Definition
A flight path that is indirect or roundabout rather than direct, often involving a longer track than a straight line between two points. In the contact approach context, ATC may deny a contact approach request if it would require the aircraft to follow a circuitous route to the airport.
Context Anchor
Seen in contact approach discussions, where the FAA explains what a contact approach is not meant to be used for.
Derivation
From Latin 'circuitus' meaning 'a going around,' from 'circum' (around) + 'ire' (to go). The same root gives us 'circuit' and 'circle.' A circuitous route literally means a path that goes around rather than straight through.
Why Pilots Care
If you request a contact approach but accepting it would require ATC to vector you the long way around (around , , or ), the may deny the request. Knowing this helps you anticipate when a contact approach is realistic and when it isn't.