Deviation from a prescribed course; a going beyond fixed limits; a digression; a trip for health or pleasure.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
A pleasure trip; a short or rapid tour.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)
A pleasure- trip; a short tour; a ramble; a digression; a wandering from the subject or main design.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (noun) (n.) (noun)
A going forth: an expedition: a trip for pleasure or health: a wandering from the main subject: a digression.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (noun) (n.) (noun)
An expedition; ramble; digression; pleasure trip.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)

Usage examples:

Now I wonder, he said thoughtfully, I wonder just what mental excursion brought you to that decision!
- An Unknown Lover by Mrs. George de Horne Vaizey
Since the day after the excursion I told you of, I take two lessons daily.
- Pepita Ximenez by Juan Valera
Though I worked myself, for the purpose of setting an example, I found time to make an excursion or two a little way into the interior.
- Hurricane Hurry by W.H.G. Kingston