Synonyms of self-interested

2 Syllables
selfish
3 Syllables
grandstanding, self-seeking, self-serving, egoistic, know-it-all
4 Syllables
egotistic, self-concerned, self-centered, self-absorbed, self-indulgent, inward-looking, self-involved, egocentric, narcissistic, independent, self-sufficient
5 Syllables
megalomaniac, egotistical, egomaniacal
6 Syllables
individualistic