Figurative use: straying from the main topic in conversation or thought.
The conversation digressed.
When we turned off the main street into a side street, it suddenly became quiet.
横道 also means 'side road' but emphasizes a road running perpendicular to the main one, while 枝道 focuses on branching off.
Antonym in figurative sense: 本筋 means 'main thread' or 'main point', opposite of digression.
Standard kanji spelling for both literal and figurative uses.
Alternate kanji spelling; less common and may be confused with 岐路 (きろ, crossroads).
Compound of 枝 (eda, 'branch') and 道 (michi, 'road'). The figurative sense extends the branching metaphor to conversation.