The Spanish word 'corno' comes from the Latin word 'cornu', meaning 'horn'. It entered Spanish through Italian 'corno', which also means 'horn'. In Spanish, 'corno' refers both to a horn (the body part or material) and specifically to a horn musical instrument.

Some related Spanish words include 'corneta' (trumpet, bugle), 'cornudo' (horned), and 'unicornio' (unicorn). All these words share the same Latin root 'cornu' and relate to horns in some way.

English speakers might recognize this root in words like 'corn' (which originally referred to a hard particle, like the hard tip of a horn), 'cornucopia' (horn of plenty), 'unicorn' (one-horned creature), and 'cornet' (a brass musical instrument). All these words trace back to the same Latin root 'cornu'.