(a.) Departing from the main subject; partaking of the nature of digression.

O-shaped aberrant aberrative aimless ambagious backhand backhanded by the way circuitous circular deflectional departing desultory deviant deviating deviative deviatory devious discursive divagational divergent episodic errant erratic excursive helical indirect labyrinthine left-handed loose maundering mazy meandering oblique orbital out-of-the-way planetary rambling rotary round roundabout roving serpentine shifting side sidelong sinister sinistral snaky spiral stray swerving turning twisting undirected vagrant veering wandering winding zigzag