Digression

Part of speech: noun (n.)

1. The act of digressing or deviating, esp. from the main subject of a discourse; hence, a part of a discourse deviating from its main design or subject. The digressions I can not excuse otherwise, than by the confidence that no man will read them. Sir W. Temple.

2. A turning aside from the right path; transgression; offense. [R.] Then my digression is so vile, so base, That it will live engraven in my face. Shak.

3. The elongation, or angular distance from the sun; -- said chiefly of the inferior planets. [R.]