ocellus

ocellus — noun

1. a very small light-sensing eye on an insect or similar animal, usually with one

1.名詞C2
釋義

a very small light-sensing eye on an insect or similar animal, usually with one lens

例句

Leo drew each ocellus above the bee's antennae in his lab notebook.

anatomy: ocellus above an insect's antennae

During class, Elena learned that dragonflies use an ocellus to detect light.

use an ocellus to detect light

同義詞
  • simple eye

    a plain descriptive term for the same kind of small visual organ

  • light-sensing eye

    a looser explanatory phrase that stresses what the organ does

用法筆記

Usually used in biology. An insect may have one or more ocelli in addition to its larger compound eyes.

常見錯誤

❌The beetle's ocellus helped it see shapes clearly.
✅The beetle's ocellus mainly helped it detect light.
💡An ocellus is simpler than a full image-forming eye.
❌The fly has two ocellus.
✅The fly has two ocelli.
💡The regular plural in scientific writing is 'ocelli'.

2. a round mark that looks like an eye, especially on a butterfly wing or peacock f

2.名詞C2
釋義

a round mark that looks like an eye, especially on a butterfly wing or peacock feather

例句

Christopher photographed the bright ocellus near the edge of the butterfly wing.

wing pattern: ocellus near the edge

At the zoo, Defne pointed to an ocellus in the peacock's tail.

ocellus in a peacock tail display

同義詞
  • eyespot

    the closest general-English term for this eye-shaped marking

  • marking

    a broader word that does not itself say the shape looks like an eye

  • spot

    an everyday general term for a small round patch of color

用法筆記

This sense names a marking, not a real eye. It often appears in descriptions of animal colors and wing patterns.

常見錯誤

❌The butterfly has an ocellus for seeing in the dark.
✅The butterfly has an ocellus on its wing.
💡In this sense, ocellus means a marking, not an actual eye.
❌The jacket's round button was an ocellus.
✅The butterfly wing had a dark ocellus near the edge.
💡Ocellus is mainly used for eye-like spots in animals.