antialtruism

The story

1. Proto-Indo-European*h₂ent-
2. Proto-Indo-European*h₂énts
3. Proto-Indo-European*h₂énti
4. Ancient Greekᾰ̓ντῐ́ (ăntĭ́)
5. Ancient Greekἀντι- (anti-)
6. Englishanti-
7. Proto-Indo-European*h₂el-
8. Proto-Indo-European*h₂élyos
9. Proto-Italic*aljos
10. Proto-Italic*aliteros
11. Latinalterī
12. Vulgar Latin*alterui
13. Old Frenchautrui
14. Frenchautrui
15. Frenchaltruisme
16. Englishaltruism
17. English todayantialtruism

From anti- + altruism.