The name Arno is a boy's name of German origin meaning "eagle". Arno and is often added to lists like Classic Baby Names with a Twist and discussed in our forums with posts like "Change One Letter".
From the experts:
Subtract the last two letters of Arnold, and you're left with a much more modern-sounding name. Arno is also the name of the main river in Florence, upon which sits the famed Ponte Vecchio. The Italian river name means "flowing water".