Divagation

n.

1.

A wandering about or going astray; digression. Let us be set down at Queen's Crawley without further divagation. - Thackeray.

Noun	1.	divagation - a message that departs from the main subject Synonyms: digression, excursus, parenthesis, aside
	2.	divagation - a turning aside (of your course or attention or concern); "a diversion from the main highway"; "a digression into irrelevant details"; "a deflection from his goal" Synonyms: digression, diversion, deflexion, deviation, deflection

aside, content, digress, digression, divagate, excursus, message, parenthesis, stray, subject matter, substance, wander