excursion vs digression

excursion and digression both are nouns.

Word	Noun	Adjective	Verb	Adverb
excursion	Yes	No	No	No
digression	Yes	No	No	No

As nouns, excursion and digression are synonyms defined as:

excursion (noun)	digression (noun)
a journey taken for pleasure	a turning aside (of your course or attention or concern)
wandering from the main path of a journey	wandering from the main path of a journey
	a message that departs from the main subject