In biology, hierarchical clustering is used to separate studied samples into different groups, thus if successful, the clustering criteria can be seen to "discriminate" between group A vs. B.

I am stuck trying to find an appropriate word to convey that two samples are so similar that they are "indiscriminable". It appears as that's not a word featured in dictionaries. I have tried "indiscernable" and that doesn't sound right either, neither does "inseparable".

What is a good adjective to use in this case? Should I try to rephrase my sentence?

PS: Please consider that this question refers to academic writing (in other words, "formal register" only).

  • 1
    Indiscriminable has certainly been used. It seems a good technical word.
    – Andrew Leach
    Mar 8, 2013 at 12:45
  • What about "almost perfectly analogous"? Mar 8, 2013 at 15:03
  • @rhetorician not sure if that would be clear enough to the audience of the article.
    – posdef
    Mar 8, 2013 at 15:06

1 Answer 1


You are very likely looking for indistinguishable:

not able to be identified as different or distinct:
the counterfeit bills were virtually indistinguishable from the real thing

  • is there a nuance difference between "indiscriminable" and "indistinguishable"?
    – posdef
    Mar 8, 2013 at 12:51
  • 1
    @posdef Perhaps not in practice. But indiscriminable appears to be a word that people use because it sounds like it exists. Googling "hierarchical clustering indiscriminable" vs. "hierarchical clustering indistinguishable" should set the matter at rest. Mar 8, 2013 at 13:02
  • Thanks, I accepted your answer as it addresses the question as it stands. I wonder however if there is another word I can use (it appears as one of my references use exactly that phrasing which I would avoid to duplicate). Does in-/non-discriminative fit, seeing as discriminative seems to be adjective form of "discriminate"?
    – posdef
    Mar 8, 2013 at 13:23
  • @posdef No, I don't think that they are proper or commonly used words. The fact that oxforddictionaries.com/definition/english/discriminable is defined as being synonymous with distinguishable further strengthens the case for indistinguishable. Mar 8, 2013 at 13:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.