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

US officials say Thursday's meeting is about Gaza but have also spoken of the "Board of Peace" in broader, amorphous terms, saying it can address other global hotspots.

From Barron's • Feb. 19, 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

“There’s barely a right angle on the entire property. Everything’s amorphous in shape.”

From Los Angeles Times • Nov. 21, 2025

Yes, the feelings themselves were intangible, amorphous, but the cause of the feelings was a matter of chemistry, biology.

From "Every Day" by David Levithan

Related Words

• nebulous
• vague