indistinguishable

indistinguishable — adjective

1. so similar to something else that the two things cannot be told apart

1.adjectiveB2
Definition

so similar to something else that the two things cannot be told apart

Example

The cheap copies were indistinguishable from the designer bags sold in stores.

indistinguishable from [noun] — comparison pattern

Kabir's twin daughters are so alike that even their teacher finds them indistinguishable.

so [adjective] that + be indistinguishable — result clause

Common collocations
  • almost indistinguishable
  • nearly indistinguishable
  • virtually indistinguishable
  • practically indistinguishable
  • barely indistinguishable
  • completely indistinguishable
Synonyms
  • identical

    stronger — means exactly the same in every detail, whereas 'indistinguishable' means a difference cannot be perceived

  • alike

    less formal; can be used after a noun ('the sisters look alike') without a preposition

  • interchangeable

    focuses on functional replaceability rather than visual similarity

Antonyms

Grammar Patterns

be indistinguishable from [something]

be + indistinguishable [between A and B]

Usage Note

Often paired with the preposition 'from' to mark the thing being compared. The subject is usually a pair or group of similar items.

Common Mistakes

The twins look indistinguishable to each other.
The twins look indistinguishable from each other.
Use 'from', not 'to', after 'indistinguishable' when drawing a comparison.

2. impossible to see, hear, or recognize clearly because of physical conditions suc

2.adjectiveC1
Definition

impossible to see, hear, or recognize clearly because of physical conditions such as distance, poor light, or background noise

Example

The writing on the old sign was so faded that it was almost indistinguishable.

so [adjective] that + be indistinguishable — visual decay

In the thick fog, the shape of the lighthouse was completely indistinguishable.

be indistinguishable + in [physical condition] — environmental interference

Common collocations
  • almost indistinguishable
  • nearly indistinguishable
  • completely indistinguishable
  • become indistinguishable
Synonyms
  • indistinct

    very close in meaning, but 'indistinct' can describe the quality itself, while 'indistinguishable' often implies a failed attempt to perceive

  • unclear

    broader in meaning — can apply to ideas or reasons, not just physical perception

  • blurry

    less formal; specifically about visual unclearness

  • faint

    applies to sounds, colors, or marks that are weak rather than mixed up

Antonyms

Grammar Patterns

be + indistinguishable

become + indistinguishable

Usage Note

Describes sensory perception (usually sight or hearing) that fails due to external conditions. This sense differs from sense 1, which compares two separate things; here a single object is unclear on its own.

Word family

Synonym discussion

Sense: adjective/1

All four words describe a lack of difference, but they are used in different ways. 'Indistinguishable' focuses on the observer's inability to perceive a difference — the items might actually be different, but you cannot tell which is which. 'Identical' means exactly the same in every detail, often used for copies or twins. 'Alike' is more general and can follow the noun it describes ('the sisters look alike'), while 'indistinguishable' usually appears after 'be'. 'Interchangeable' means each item can replace the other without changing the result, which is common for machine parts or roles. For example: 'The two pens are indistinguishable in a dark room' (your eyes cannot tell). 'The two pens are identical' (same brand, same colour). 'The two pens are interchangeable' (you can use either one).

indistinguishable ↗identical ↗alike ↗interchangeable

Common collocations

Adverbs

Phrases

  • so similar that... is indistinguishable

Prepositions

Etymology

LatinFrenchEnglish

Formed from the prefix 'in-' (meaning 'not') and 'distinguishable' (able to be told apart), which comes from Latin 'distinguere' (to separate, mark off by pricking). The word entered English in the early 1600s.