Selfishness is a masculine noun that names a excessive self-love, which leads an individual to look only at their opinions, interests and needs, and who despises the needs of others.
Selfishness is an exclusivism that makes the individual refer everything to himself. It's a pride, a presumption.
The person who deals only with their interests, who carries the feelings of selfishness with them, is adjectived of selfish.
In psychology, the intellectual attitude of the one who is all about self is called self-centeredness.
Selfishness is a behavior that leads the individual to desire total exclusivity over the feelings of others, generating jealousy, a negative feeling, which when exaggerated becomes paranoia.
The opposite of selfishness is altruism, that is, a behavior of those who love their neighbors, who are selfless, in solidarity with others.
For Buddhists, when reaching the state of Nirvana, through meditation, one arrives at liberation, considered the last stage to be reached by Buddhist philosophy. In it, it is possible to get rid of selfishness, pride, envy, etc. feelings that afflict the human being.