boss

noun

1.
a person who exercises control over workers
headwright chief foreman gaffer honcho
Derived from:
bossy
2.
a person responsible for hiring workers
hirer
3.
a person who exercises control and makes decisions
hildwiser
4.
a leader in a political party who controls votes and dictates appointments
party boss political boss
5.
a circular rounded projection or protuberance
knop knosp knurl knob
Derived from:
boss