outfall vs outlet

outfall and outlet both are nouns.

Word	Noun	Adjective	Verb	Adverb
outfall	Yes	No	No	No
outlet	Yes	No	No	No

As nouns, outlet is a hypernym of outfall; that is, outlet is a word with a broader meaning than outfall:

Other hypernyms of outfall include exit, issue, way out.

outfall (noun)	outlet (noun)
the outlet of a river or drain or other source of water	activity that frees or expresses creative energy or emotion
	an opening that permits escape or release
	a place of business for retailing goods
	receptacle providing a place in a wiring system where current can be taken to run electrical devices