What is the meaning of Cornu?

A horn, or anything shaped like or resembling a horn.

A brass instrument from Ancient Rome about 3 metres long in the shape of a letter 'G'.

horn

cornel, European cornel, Cornus mas

horn

horned

a horn, antler

a tusk

the horns of the moon

an arm or wing of an army

a bow

a horn as a musical instrument

any substance like the material of a horn, such as the bill of a bird

the end of a book or scroll, usually made of ivory

power, strength, might

Source: wiktionary.org