Divagate \DAHY-vuh-geyt\ , verb;
1. To wander; stray
2. To digress in speech
According to Etymonline.com:
Divagate dates to the 1590's and comes from Latin divagatus, which is the past participle of divagari ("to wander about"). It comes from a combination of di(s)- + vagari ("apart" + "to wander, ramble"). Vagari is also a predecessor of vague.
*Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Friday, December 3