Word.ws English Dictionary

actinal

actinal adjective: pertaining to the side or surface around the mouth in an animal that has radial symmetry such as a starfish.

Adjective

actinal

  1. Pertaining to the side or surface around the mouth in an animal that has radial symmetry such as a starfish.
    • The so-called mouth is always placed at one of these poles, and from it radiate the most prominent organs, in consequence of which I have called this side of the body the oral or actinal area ...1857, Professor Louis Agassiz, Natural History of North America, Vol. IV, page 376
    Antonyms:
    abactinal
  2. Pertaining to the axis of rotational symmetry in radiate animals.
    • [Professor Agassiz] gives the names of two axes of the animals; that around which the motion of the animal occurs is the actinal axis ...1861, John Timbs, Charles W. Vincent, James Mason, The Year-book of Facts in Science and Art, Simpkin, Marshall, and Co., page 214

Antonyms of actinal

Origin of actinal

From Ancient Greek ἀκτίς, ἀκτῖν- (aktís, aktîn-, “ray”) + -al. The usage was coined by Louis Agassiz (See quotations below.).

Words formed from actinal

Questions about actinal

What does actinal mean?
Actinal means pertaining to the side or surface around the mouth in an animal that has radial symmetry such as a starfish.
What part of speech is actinal?
Actinal is an adjective.

Words near actinal in the dictionary

  1. actimetry
  2. actimycin
  3. actin
  4. actin'
  5. actin-
  6. actinal
  7. actinally
  8. actinarian
  9. actinarians
  10. actinase
  11. actinases

Source and license

Adapted from Wiktionary: actinal (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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