calamus

calamus — noun

1. A tall plant that grows in shallow water and wet ground, with long sword-shaped

1.nounC2
Definition

A tall plant that grows in shallow water and wet ground, with long sword-shaped leaves and roots that give off a strong spicy smell.

Example

Keiko planted calamus along the edge of her small garden pond.

collocation: calamus + pond

The calamus growing by the drainage ditch gave off a spicy scent.

Common collocations
  • calamus grows in
  • patch of calamus
  • calamus leaves
  • calamus roots
Synonyms
  • sweet flag

    the common English name for the same plant; less formal than calamus

  • Acorus calamus

    scientific Latin name used in botanical writing

2. The peeled and dried underground stem of sweet flag, once valued as a flavouring

2.nounC2
Definition

The peeled and dried underground stem of sweet flag, once valued as a flavouring for food and drink and still used in some traditional herbal remedies.

Example

Dimitri's grandmother kept dried calamus in a jar for stomach complaints.

collocation: dried calamus

The old apothecary sold calamus as a remedy for digestive troubles.

collocation: sold calamus as a remedy

Common collocations
  • dried calamus
  • chew calamus
  • calamus oil
  • piece of calamus
Synonyms

3. The stiff, hollow tube at the base of a feather, lying beneath the soft, flat pa

3.nounC2
Definition

The stiff, hollow tube at the base of a feather, lying beneath the soft, flat part where the barbs spread out.

Example

Svetlana examined the calamus under a magnifying glass during biology class.

The calamus of an eagle feather is surprisingly strong for its size.

collocation: calamus of a feather

Common collocations
  • calamus of a feather
  • hollow calamus
  • broken calamus
  • split the calamus
Synonyms
  • quill

    broader term; can mean the whole feather shaft, a feather pen, or specifically the hollow base

  • feather base

    plain-English equivalent used outside scientific contexts

Usage Note

A technical term used in ornithology. In everyday speech, most people say 'the base of the feather' or simply 'quill' — though 'quill' can also mean the entire central shaft or a writing instrument made from a feather.

Common Mistakes

He wrote with a calamus.
He wrote with a quill.
A calamus is only the hollow base of a feather, not a writing instrument. Use 'quill' for a feather pen.

Word family

  • calami
    nounC2
  • calamoid
    adjectiveC2

Synonym discussion

Sense: noun/1

Calamus (sweet flag) is often confused with other tall water plants, but each has distinct features. A reed has a tall, hollow stem and feathery flower heads and grows in dense stands. A rush has round, solid stems and small brown flower clusters. A cattail has a thick, brown, sausage-shaped flower spike that makes it unmistakable. A bulrush is similar to a cattail but has a looser, branching flower head. Calamus stands apart because of its sword-shaped leaves that release a spicy, citrus-like scent when crushed — none of the others share this fragrance. If you are walking near a pond and crush a leaf that smells like ginger and cinnamon, you have found calamus.

reed ↗rush ↗cattail ↗bulrush ↗

Etymology

GreekLatinEnglish

Calamus entered English in the late 14th century through Latin, where it meant 'reed, cane, or pen.' The Latin word was borrowed from Greek kalamos (κάλαμος), which also meant 'reed' or 'stalk.' The plant sense developed because the sweet flag's tall, slender stems resemble reeds. The feather sense comes from the same Latin root — Romans used hollow reeds as writing pens, and by extension, the hollow base of a feather was given the same name. So the plant, the root, and the feather part all trace back to a single ancient word for a hollow reed.

First known use

14th century

14th century, in the meaning defined at sense 1a