Strongest:
* Altruism: This is the most common word for complete selflessness, denoting a concern for the welfare of others. It implies a disinterested and selfless act.
* Abnegation: This refers to the act of renouncing or denying oneself, especially for a higher purpose. It implies a complete sacrifice of personal desires.
Other options:
* Selflessness: This is a straightforward word, simply meaning a lack of selfishness.
* Unselfishness: Similar to selflessness, but emphasizing the lack of self-interest.
* Benevolence: This implies a kind and generous nature, often motivated by a desire to help others.
* Sacrifice: This refers to giving up something valuable for the benefit of others.
* Charity: This implies giving generously to those in need.
The best word to use will depend on the specific context and the nuance you want to convey.