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.

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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

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amorphous Scientific  

/ ə-môr′fəs /

1. Not made of crystals. Glass, amber, and plastics are amorphous substances.

2. Lacking definite form or shape.

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Other Word Forms

• amorphism
  noun
• amorphously
  adverb
• amorphousness
  noun

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.

Example Sentences

“Another more amorphous change is the culture…the new Boeing sounds a lot more like what Airbus would call humble, and that is no bad thing.”

From Barron's • Jan. 28, 2026

Instead, it becomes an amorphous solid, a form of metal without the ordered structure of a crystal.

From Science Daily • Dec. 11, 2025

What started as a serious but short-lived spike in inflation from 2021 to 2023 has evolved into something broader and more amorphous.

From The Wall Street Journal • Nov. 23, 2025

“I don’t know if I could replicate it because I find that the algorithm is this kind of amorphous, ever-changing, mystical thing that no one can ever really crack,” James said.

From Los Angeles Times • Oct. 22, 2025

Either common sense is amorphous and malleable, to the extent that all the beliefs that are shared within a community are compatible with common sense.

From "The Invention of Science" by David Wootton

Related Words

• nebulous
• vague