singularity

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The quality or condition of being singular.
2. n. A trait marking one as distinct from others; a peculiarity.
3. n. Something uncommon or unusual.
4. n. Astrophysics A point in space-time at which gravitational forces cause matter to have infinite density and infinitesimal volume, and space and time to become infinitely distorted.
5. n. Mathematics A point at which the derivative does not exist for a given function but every neighborhood of which contains points for which the derivative exists. Also called singular point.

Century Dictionary and Cyclopedia

1. n. The state or character of being singular. Existence as a unit, or in the singular number.
2. n. Separateness from others; solitariness; specifically, celibacy.
3. n. Individualism, as in conduct, opinion, characteristics, etc.
4. n. Uniqueness; the state of having no duplicate, parallel, or peer.
5. n. Unusualness; rareness; uncommon character; hence, specifically, rare excellence, value, eminence, or note.
6. n. Variation from established or customary usage; eccentricity; oddity; strangeness.
7. n. That which is singular; a singular person, thing, event, act, characteristic, mood, or the like; especially, an individual or personal peculiarity.
8. n. In mathematics, an exceptional element or character of continuum. in geometry, a projective character of a locus consisting in certain points, lines, or planes being exceptional in their relations to it. (For examples, see binode.) An ordinary singularity is one of a set of singularities of which all others are modifications or compounds. Thus, an actual node upon a skew curve is a modiflcation of an apparent node, and ought not to be reckoned as an ordinary singularity. But cusps and inflections, as stationary points and tangents, are ordinary singularities. A higher singularity is one which differs indefinitely little from an aggregation of ordinary singularities. (See tacnode.) By an ellipsis common in geometrical language, the word singularity is used for point-singularity, or a relation to some exceptional point. Thus, a plane curve with neither nodes nor cusps is said to be without singularities, although, unless a conic, it has inflections, and unless a conic or cubic, double tangents. The word singularity is also used to denote the number of singular points, lines, or planes of any one kind; also for any number characteristic of a projective property, in which sense the order, class, and rank of a locus are sometimes termed singularities.
9. n. Synonyms Uncommonness, oddness.
10. n. Idiosyncrasy. See eccentric.

Wiktionary

1. n. the state of being singular, distinct, peculiar, uncommon or unusual
2. n. a point where all parallel lines meet
3. n. a point where a measured variable reaches unmeasurable or infinite value
4. n. mathematics the value or range of values of a function for which a derivative does not exist
5. n. physics a point or region in spacetime in which gravitational forces cause matter to have an infinite density; associated with black holes
6. n. A proposed point in the technological future at which artificial intelligences become capable of augmenting and improving themselves, leading to an explosive growth in intelligence.
7. n. obsolete Anything singular, rare, or curious.
8. n. obsolete Possession of a particular or exclusive privilege, prerogative, or distinction.
9. n. obsolete celibacy

GNU Webster's 1913

1. n. The quality or state of being singular; some character or quality of a thing by which it is distinguished from all, or from most, others; peculiarity.
2. n. Anything singular, rare, or curious.
3. n. Possession of a particular or exclusive privilege, prerogative, or distinction.
4. n. obsolete Celibacy.

WordNet 3.0

1. n. strangeness by virtue of being remarkable or unusual
2. n. the quality of being one of a kind