Kalamos (Template:Lang-el; Template:Lang-la) is an ancient Greek word meaning reed or reed pen. The basis for this meaning is the story of the Greek mythological figure Kalamos, son of Maiandros (god of the Maeander river).

A story in Nonnus's Dionysiaca tells about the love of two youths, Kalamos and Karpos, the son of Zephyrus and Chloris. Karpos drowned in the Meander river while the two were competing in a swimming contest. In his grief, Kalamos allowed himself to drown also. He was then transformed into a water reed, whose rustling in the wind was interpreted as a sigh of lamentation.^[1]

Walt Whitman's "Calamus" poems in Leaves of Grass may have been inspired by this story.^{[citation needed]}

Similar words can be found in Sanskrit (kalama, meaning "reed" and "pen" as well as a type of rice), Hebrew (kulmus, meaning quill) and Latin (calamus). These words are most likely derived from the ancient Greek term kalamos. The Arabic word قلم qalam (meaning "pen" or "reed pen") is likely to have been borrowed from one of these languages in antiquity. The Swahili word kalamu ("pen") comes from the Arabic qalam.

From the Latin calamus come a number of modern English words:

• calamus (aka Sweet Flag), a wetland reed;
• calamari, meaning "squid", via the Latin calamarium, "ink horn" or "pen case", as reeds were then used as writing implements;
• calumet, another name for the Native American peace pipe, which was often made from a hollow reed;
• shawm, a medieval oboe-like instrument (whose sound is produced by a vibrating reed mouthpiece);
• chalumeau register, the lower notes of a clarinet's range (another reed instrument).

• Qalam, Arabic pen