Selfless means putting the good of others before your own. A selfless act, selfless devotion, entirely selfless.
It is high praise and is used most in citations for bravery, where selfless is nearly a technical term. Whether anything is completely selfless is an old argument, since doing good feels good, but the question is more interesting than it is useful.
1adjectiveselflessPutting the good of others before your own.
“The nurse's selfless care for her patients, even on her days off, moved everyone.”
selfless is a quality.
Middle English
self
English
self
English, today
selfless
From self + -less. self comes from Middle English self. From Middle English salve, self, silf, from Old English self, seolf, sylf, from Proto-Germanic selbaz, from Proto-Indo-European selbʰ- (“one's own”). 2
Etymology from Wiktionary, CC BY-SA