from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Impossible to define, describe, or analyze. See Synonyms at unspeakable.
- n. One that is indefinable.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. That cannot be precisely defined or put into words
- adj. That defies description; indescribable
- n. Anything that cannot be defined.
from the GNU version of the Collaborative International Dictionary of English
- adj. Incapable of being defined or described; inexplicable.
from The Century Dictionary and Cyclopedia
- Not definable; incapable of being defined or exactly described; not susceptible of definition: as, an indefinable boundary; an indefinable word; indefinable sensations.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. not capable of being precisely or readily described; not easily put into words
- adj. defying expression or description
 Exemplary as defined through critical reception, financial success and a certain indefinable presence as part of popular culture.
= “Who cares if the person is right for the job, as long as the person is opposite of what a certain indefinable group of people want.”
Except for his impeccably accented English and a certain indefinable air about his bearing (I always say no one slouches quite as elegantly as an Englishman), an observer might have taken my son for one of the Egyptians among whom he had spent most of his life.
Hers was an extreme lithesomeness, and she moved with a certain indefinable airiness, approaching one as down might float or as a bird on noiseless wings.
The features, look, air, portrait, the expression indefinable except as a light of outcoming spirit, were those of the man he had helped crucify before the
I look for style, structure, prose, originality and a certain indefinable quality that makes me curse and say, “Damn, I wish I’d thought of that.”
He thought of the unknown as the indefinable beyond to an immediate world that might be quite clearly and exactly known.
He thought, it seems to me, of the unknown as the indefinable Beyond of an immediate world that might be quite clearly and definitely known.
The demon Ware looked directly and challengingly at Adria with his many-colored eyes, all the colors of which had darkened with some kind of indefinable emotions.
We had come to probe its mystery, we had hoped to reduce it to terms of science, but there was always the "indefinable" which held aloof, yet riveted our souls.