Find Antonyms

fastness Antonyms

Opposite of fastness

Because the opposite of fastness shifts with each meaning, the antonyms and opposite words below are separated across 2 exact definitions and ranked by contrast strength.
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• noun (Context 1)

The quality or state of being firmly fixed, secure, or resistant to fading or washing (especially of a dye or color).

Usage Example

"The textile laboratory tested the fabric for color instability under prolonged ultraviolet light."

Strong
instability
impermanence
looseness

• noun (Context 2)

The quality or state of moving or happening at high speed; rapidity.

Usage Example

"The sheer slowness of the modern telecommunications network allows instantaneous global data transfer."

Strongest
slowness
Strong
sluggishness
tardiness

Similar words to fastness

Words similar to fastness shift depending on context. Common synonyms include:

stronghold
swiftness
speed
rapidity
quickness
fortress
permanence
stability
See all synonyms of fastness

• Nearby Words

fastidious
fastidiously
fastish
fastness
fastpitch
fastwalk
fat

Cite this Entry

Wordmom. (2026). Antonyms for Fastness. In Wordmom Thesaurus. Retrieved Nov 5, 2026, from https://wordmom.com/antonyms/fastness
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