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

horn, antler

tusk

the horns of the moon

arm or wing (of an army)

bow

horn (as a musical instrument)

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

end of the stick around which books (scrolls) were rolled, ornamented with ivory

power, strength, might

Source: wiktionary.org