individuality

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The aggregate of qualities and characteristics that distinguish one person or thing from others; character: choices that were intended to express his individuality; monotonous towns lacking in individuality.
2. n. An individual or distinguishing feature.
3. n. The quality or state of being individual; singularity: She was so absorbed by the movement that she lost all sense of individuality.
4. n. A single, distinct entity.
5. n. Archaic Indivisibility.

Century Dictionary and Cyclopedia

1. n. The condition or mode of being individual. The being individual in contradistinction to being general.
2. n. The particular or distinctive character of an individual; that quality, or aggregate of qualities, which distinguishes one person or thing from another; idiosyncrasy: as, a person of marked individuality.
3. n. A personality; a personage; an individual.
4. n. The existence, efforts, interests, or concerns of the individual as distinguished from the interests or concerns of the community.
5. n. In biology:
6. n. Physiological completeness or independence; the ability of an organism to perform its normal functions or live out its life without the cooperation of others. The independence of a unicellular protozoon is an example of physiological individuality, as contrasted with the dependence of one of the cells of a metazoon upon the others and the whole. A physiological individual is sometimes termed a bion, as contrasted with a morphological individual or morphon. See bion and morphon, 2.
7. n. Structural independence, or homology with or morphological equivalence to a physiological individual. The homology of each of the dependent members of a siphonophore with an independent hydra is an illustration of morphological individuality. So far as each of the constituent cells in the body of a metazoon is homologous with an independent protozoon it is a morphon, or morphological individual. Morphologists recognize and give names to several grades or categories of morphological individuality. See plastid, idorgan, person, 8, and cormus, 3.
8. n. The uniqueness of a living being, or its difference from others of its kind and from the rest of nature. It is in this sense that the offspring is said to inherit the individuality or constitution of a parent.

Wiktionary

1. n. uncountable The characteristics which contribute to the differentiation or distinction of someone or something from a group of otherwise comparable identity.
2. n. countable A person.

GNU Webster's 1913

1. n. The quality or state of being individual or constituting an individual; separate or distinct existence; oneness; unity.
2. n. The character or property appropriate or peculiar to an individual; that quality which distinguishes one person or thing from another; the sum of characteristic traits; distinctive character.
3. n. A habit of thinking and acting in one's own distinctive manner and as one believes appropriate, not being heavily influenced by the opinions of others; -- of people.

WordNet 3.0

1. n. the distinct personality of an individual regarded as a persisting entity
2. n. the quality of being individual