What is the meaning of Motherfucker?

Expressing dismay, discontent, or surprise.

An extremely contemptible, vicious or mean person.

Any person, often but not always with the connotation that the person is disliked or is threatening.

An extremely intense experience, often but not always negative.

To an extreme degree.

A good very close friend or relative.

One who engages in incest with their mother.

One who engages in sex with a mother, not necessarily one's own.

motherfucker, n.”, in OED Online Paid subscription required, Oxford, Oxfordshire: Oxford University Press, launched 2000.

Source: wiktionary.org