ocellus

[ oh-sel-uhs ]

noun

, plural o·cel·li [oh-, sel, -ahy].

1. a type of simple eye common to invertebrates, consisting of retinal cells, pigments, and nerve fibers.
2. an eyelike spot, as on a peacock feather.

ocellus

/ ˈɒsɪˌleɪt; ˈɒsɪˌleɪtɪd; ɒˈsɛləs /

noun

1. the simple eye of insects and some other invertebrates, consisting basically of light-sensitive cells
2. any eyelike marking in animals, such as the eyespot on the tail feather of a peacock
3. botany
   1. an enlarged discoloured cell in a leaf
   2. a swelling on the sporangium of certain fungi

ocellus

/ ō-sĕl′əs /

, Plural ocelli ō-sĕl′ī′

1. A small, simple eye or eyespot, found in many invertebrates.
2. A marking that resembles an eye, as on the wings of some butterflies.

Derived Forms

• ˌocelˈlation, noun
• oˈcellar, adjective
• ocellate, adjective

Word History and Origins

Origin of ocellus¹

1810–20; < Latin: little eye, diminutive of oculus eye; -elle

Word History and Origins

Origin of ocellus¹

C19: via New Latin from Latin: small eye, from oculus eye

Example Sentences

Some species also have three simple light-detecting eyes, called ocelli, to help them fly and navigate, in addition to the standard two compound eyes.

From New York Times

The orange spots are ocelli, but toward the lower right they are starting to be clustered into structures that might be described as eyes.

From Scientific American

The worms have also evolved ocelli on their crown of feathery tentacles, which look like dustings of orange pollen.

From National Geographic

They are thus able, like real ocelli, to track the sun.

From Economist

Dragonflies also have three smaller eyes, called ocelli.

From Washington Post