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amorphous

American  
[uh-mawr-fuhs] / əˈmɔr fəs /

adjective

  1. lacking definite form; having no specific shape; formless.

    the amorphous clouds.

    Synonyms:
    anomalous, vague, undefined, shapeless
  2. of no particular kind or character; indeterminate; having no pattern or structure; unorganized.

    an amorphous style; an amorphous personality.

    Synonyms:
    anomalous, vague, undefined, shapeless
  3. Petrography, Mineralogy. occurring in a mass, as without stratification or crystalline structure.

  4. Chemistry. not crystalline.

  5. Biology. having structural components that are not clearly differentiated, as the nuclear material in certain bacteria.


amorphous British  
/ əˈmɔːfəs /

adjective

  1. lacking a definite shape; formless

  2. of no recognizable character or type

  3. (of chemicals, rocks, etc) not having a crystalline structure

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

amorphous Scientific  
/ ə-môrfəs /
  1. Not made of crystals. Glass, amber, and plastics are amorphous substances.

  2. Lacking definite form or shape.


Other Word Forms

Etymology

Origin of amorphous

First recorded in 1725–35, amorphous is from the Greek word ámorphos shapeless. See a- 6, -morph, -ous

Explanation

Amorphous means without a clearly defined form, like the moon's amorphous reflection in a lake. Figuratively, something amorphous lacks focus, be it a work of art, a political movement, or even someone's life plans. The Greek roots of this word are clear: morphē means "form," and a- means "lacking or without." When creative works or ideas are described as amorphous, it means they suffer from a lack of organization. An amorphous object lacks a well-defined outline or structure, like amorphous jellyfish drifting on the surface of the ocean. And scientifically, this adjective simply describes something without a crystalline form, like an amorphous metal or amorphous ice.

Keep Reading on Vocabulary.com

Vocabulary lists containing amorphous

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

It’s hard even for a healthcare insider to navigate the system, let alone appeal a denial with amorphous reasoning behind it.

From MarketWatch Sep. 8, 2026

Digital disaffection has bled into our lives like dye onto white linen, creeping through every inch of the fabric until it’s covered in amorphous patterns of color; some beautiful, some painfully ugly.

From Salon Aug. 24, 2026

Electability can be a frustratingly amorphous concept—one that isn’t always fair either.

From Slate Aug. 12, 2026

Made from amorphous silica, a form of silicon dioxide found naturally in foods and the fossilized remains of microscopic organisms, the engineered nanoparticles appear to attack prostate cancer in multiple ways at once.

From Science Daily Jul. 9, 2026

So I just enjoyed the feeling and watched the once amorphous student body separate itself into hundreds of individuals.

From "Stargirl" by Jerry Spinelli

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