What does "bossism" mean?

The domination of a political party by a single, powerful person (the boss)

Bossism

Common synonyms include: arbitrariness, authoritarian leadership, authoritarianism, authoritativeness, autocratic leadership, autocraticalness.

noun

noun ·Uncommon ·Advanced level

Noun

1
The domination of a political party by a single, powerful person (the boss) US, uncountable, usually
2
domination of a political organization by a party boss wordnet

From boss + -ism.