Arno

American  

[ahr-noh, ahr-naw] / ˈɑr noʊ, ˈɑr nɔ /

noun

1. Peter Curtis Arnoux Peters, 1904–68, U.S. cartoonist and author.

2. a river flowing W from central Italy to the Ligurian Sea. 140 miles (225 km) long.

---

Arno British  

/ ˈɑːnəʊ /

noun

1. a river in central Italy, rising in the Apennines and flowing through Florence to the Ligurian Sea. Length: about 240 km (150 miles)

---

Example Sentences

Years back, one of its Nobel laureates, Arno Penzias, told me: “You have to understand, this was a problem-rich environment.”

From The Wall Street Journal • Mar. 28, 2026

The Swiss pair of Arno Lietha and Jon Kistler had led up the initial gruelling 65-metre climb in heavy snow in northern Italy.

From Barron's • Feb. 19, 2026

Greg Torosian and Arno Vardanyan are also seeking third titles for the Patriots in boys.

From Los Angeles Times • Feb. 14, 2026

During a recent field expedition, researchers Heinz Arno Drawert and Thomas Otto Litz made a breakthrough.

From Science Daily • Dec. 25, 2025

In 1965 two American physicists at the Bell Telephone Laboratories in New Jersey, Arno Penzias and Robert Wilson, were testing a very sensitive microwave detector.

From "A Brief History of Time: And Other Essays" by Stephen Hawking