alpha male

noun
1.
a male animal having the highest rank in a dominance hierarchy:
Studies show that in spite of their high rank, access to females, etc., baboon alpha males experience a great deal of stress.
2.
the most dominant, powerful, or assertive man in a particular group:
the alpha male of investment bankers.
British Dictionary definitions for alpha male

alpha male

noun
1.
the dominant male animal or person in a group
Contemporary definitions for alpha male
noun

a domineering man; the dominant member in a group of males, esp. animals

Examples

Alpha male traits have been widely seen recently in American politics.

Word Origin

from first letter of the Greek alphabet, often used as an adjective to describe males and females of species who rank first in a group