costa

costa — noun

1. in anatomy, one of the curved chest bones that enclose the heart and lungs in hu

1.nounC2
Definition

in anatomy, one of the curved chest bones that enclose the heart and lungs in humans and other vertebrates; in botany and zoology, any firm narrow supporting part similar to a rib — for instance, the main vein running lengthwise through a leaf blade, or the thickened forward edge on the wing of an insect

Example

Dr. Walid saw a crack in the patient's costa on the chest X-ray.

domain: medical / X-ray imaging

In a rose leaf, the costa runs from the stem to the tip.

collocation: costa of a leaf

Common collocations
  • fractured costa
  • first costa
  • costa of a leaf
  • costa of the wing
  • left costa
  • right costa
Synonyms
  • rib

    everyday word for the same bone; 'costa' is the formal medical/anatomical term

  • midrib

    the central vein of a leaf; 'costa' is the scientific name for this structure

  • vein

    general term for any tubular structure in a leaf or insect wing; 'costa' is a specific vein along the front edge of an insect wing

Grammar Patterns

the + costa + of + [body part / plant / insect]

Usage Note

This is a formal scientific term used mainly in anatomy, botany, and zoology. In everyday conversation, English speakers use the word 'rib' instead. The Latin plural form 'costae' (pronounced /ˈkɒstiː/) is often used in medical writing.

Common Mistakes

I think I broke my costa.
I think I broke my rib.
'Costa' is a technical term; use 'rib' in ordinary speech.
The leaf has many costae.
The leaf has one main costa (midrib) and many smaller veins.
'Costa' refers only to the central vein or midrib, not to all the veins.

Word family

  • costal
    adjectiveC2
  • intercostal
    adjectiveC2
  • costate
    adjectiveC2
  • costiform
    adjective

Synonym discussion

Sense: noun/1

'Costa' is the formal scientific term for a 'rib' in anatomy and biology. In everyday English, people say 'rib' (e.g., 'I fell and hurt my rib'), while doctors and biologists prefer 'costa' in medical reports or textbooks ('the patient suffered a fractured left costa'). In botany, 'costa' and 'midrib' both refer to the central vein of a leaf, but 'midrib' is more common in gardening guides, whereas 'costa' appears in academic descriptions. In entomology, the 'costa' is the thick supporting vein along the front edge of an insect wing — a different structure from the smaller 'veins' that branch across the wing surface. A useful guideline: use 'rib' for casual conversation, 'costa' for formal scientific writing, and 'midrib' or 'vein' when describing plants and insects to a general audience.

rib ↗midribvein ↗

Common collocations

Nouns

Phrases

  • first costa
  • costa of a leaf

Prepositions

Etymology

LatinEnglish

From Latin 'costa', meaning 'rib' or 'side'. The word was adopted into English during the 14th century through medical and anatomical writings. In modern biology, its meaning expanded from the human chest rib to include any rib-like supporting structure in plants (leaf midrib) and insects (wing vein). The related adjective 'costal' ('relating to the ribs') and the prefix 'costo-' (as in 'costochondral') are common in medical terminology.