without concern for gain or greed; single-mindedly
Describes a state of acting purely out of a desire to do something, without any selfish motives or calculation of personal benefit. Often used when someone is so absorbed in an activity that they forget about profit or loss.
He continues volunteering without any thought of personal gain.
I like painting just for the sake of it, without caring about profit or recognition.
A set phrase combining 欲 (desire, greed) and 得 (gain, profit) with the negative ない, literally 'there is neither desire nor gain.' The exact origin is uncertain, but it likely arose from the idea of acting without any thought of personal benefit.