fissure

/ˈfɪʃə(r)/ (bre, ipa) · /ˈfɪʃər/ (ame, ipa) · /ˈfi-shər/ (ame, mw)

fissure — noun

  • fissuresingular
  • fissuresplural

1. a long deep narrow opening that appears in the surface of rock or ground, often

1.名詞B2
釋義

a long deep narrow opening that appears in the surface of rock or ground, often caused by movement, pressure, or changes in temperature

例句

After the earthquake, a deep fissure appeared across the highway near the mountain village.

collocation: deep fissure

Rainwater seeped into a narrow fissure in the limestone cliff and widened it for years.

verb + into + fissure (seeped into)

同義詞
  • crack

    more general term; a crack can be shallow or short, while a fissure is usually long and deep

  • crevice

    a narrow crack, especially in rock; similar meaning but often smaller than a fissure

  • rift

    a large, serious crack that suggests separation; often used for gaps caused by movement of the earth's plates

  • chasm

    much wider and deeper than a fissure; often describes a gap large enough to be dangerous

用法筆記

Collocates with 'deep', 'narrow', and 'wide' to describe size; 'form', 'appear', 'open up' are common verbs describing how a fissure comes into being.

常見錯誤

❌A deep crack appeared in the earth.
✅A deep fissure appeared in the earth.
💡'crack' is more general; 'fissure' specifically describes a long, deep, narrow opening, especially in rock or ground.

2. a long narrow groove or indentation that naturally occurs on the surface of an o

2.名詞C1
釋義

a long narrow groove or indentation that naturally occurs on the surface of an organ or body part, such as those that divide the brain into sections

例句

The surgeon carefully examined the deep fissure that separates the two hemispheres of the brain.

collocation: separates the two hemispheres

These natural fissures in the cerebral cortex help divide the brain into different functional areas.

domain: cerebral cortex

同義詞
  • groove

    a shallower indentation; anatomical grooves (sulci) are less deep than fissures

  • cleft

    a split or division; used for natural separations in the body such as the cleft palate

  • sulcus

    the technical term for a groove on the brain's surface; fissures are deeper than sulci

用法筆記

Almost always used in medical or anatomical writing. The most common reference is to the longitudinal fissure that separates the brain's left and right hemispheres.

常見錯誤

❌The doctor found a crack in the patient's brain.
✅The doctor found a fissure in the patient's brain.
💡'crack' suggests damage; 'fissure' is the correct anatomical term for a normal groove or for a pathological split.

3. a narrow crack or natural line in the hard outer surface of a tooth, which can t

3.名詞C1
釋義

a narrow crack or natural line in the hard outer surface of a tooth, which can trap food and bacteria

例句

The dentist filled a small fissure on Jamal's back molar to prevent decay.

collocation: fill a fissure

Food particles can easily get trapped in a deep fissure and cause cavities over time.

同義詞
  • groove

    less precise; 'groove' is a general term while 'fissure' specifically describes the deep narrow lines on molars

  • pit

    a small hole rather than a line; pits and fissures are often mentioned together in dentistry

用法筆記

In dentistry, 'fissure' refers specifically to natural grooves on the chewing surfaces of molars and premolars. These are not signs of damage but normal features that may need sealing.

常見錯誤

❌The dentist found a crack in my tooth that needs filling.' (when referring to a natural groove)
✅The dentist sealed the deep fissure on my tooth.
💡a 'crack' suggests damage; a 'fissure' in a dental context is a normal groove that can be sealed protectively.

fissure — verb