self-partiality

noun

self-par·​tial·​i·​ty ˌself-ˌpär-shē-ˈa-lə-tē 

-ˌpär-ˈsha-

1

: an excessive estimate of oneself as compared with others

2

: a prejudice in favor of one's own claims or interests

Word History

First Known Use

1628, in the meaning defined at sense 1