An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Of, pertaining to, or noting two; having a twofold, or double, character or nature.

From L. dualis, from duo "two."

Dogâné, from do "two," cognate with duo + -gân plurality suffix + -é nuance suffix.

The outcome of a → merger process between two galaxies, each with its own central → supermassive black hole (SMBH), resulting in a remnant galaxy hosting two SMBHs. Simulations of → galaxy mergers show there should be lots of dual → active galactic nuclei (AGN) visible at less than 10 kpc separations. As of 2015 more than 100 known dual supermassive black holes have been found. See also → binary supermassive black hole.

→ dual; → supermassive; → black; → hole.

1) Philo.: The doctrine, as opposed to idealism and materialism, that reality consists of two basic types of substance usually taken to be mind and matter or two basic types of entity, mental and physical.
2) The state of being twofold or double. → dualism, → pluralism (Dictionary.com).

→ dual; → -ism.

The quality or character of being twofold, as the → wave-particle duality.

M.E dualitie, from L.L. dualitas.

Dogânegi, from dogânag + -i.

Proceeding, taking place, changing by small degrees.

From M.L. gradualis, from L. gradus "step."

Padâkvâr, from padâk "grade," + -vâr a suffix which denotes "suiting, befitting, resembling, in the manner of, possession."
Pâypâyé "step by step," from pây, pâ "foot, step," → foot.

A burst that happens gradually, in contrast to a sudden burst.

→ gradual; → burst.

1a) A single human being, as distinguished from a group (Dictionary.com).
1b) A distinct, indivisible entity; a single thing, being, instance, or item (Dictionary.com).
1c) Logic: An → object or element taken as the → subject of the → predicates of → first-order logic.
2) Of, pertaining to, or characteristic of a particular person or thing. → individual constant, → individual variable.

M.E., from M.L. individualis, from L. individuus "indivisible," from → in- "not, opposite of" + dividuus "divisible," from dividere, → divide.

Takâl, from tak, → single, + suffix -âl, → -al; takâli with adj. suffix -i.

In predicate logic: A → word or → expression that represents a → specific  → individual or → object. A single object can be denoted by multiple individual constants, reflecting the fact that objects can have multiple names. On the other hand, any individual constant can only denote one object. Individual constants are represented by lower case letters from the beginning of the alphabet: a, b, c.

→ individual; → constant.

In → predicate logic, a variable which represents an unspecified → subject. Individual variables work just as do variables in algebra, they stand in for a value, but have no fixed value of their own. They are represented by lower case letters taken from the end of the alphabet x, y, z; and if additional variables are needed by u, v, w, as well.

→ individual; → variable.

1) A social theory advocating the liberty, rights, or independent action of the individual (Dictionary.com).
2) An individual peculiarity.

→ individual; → -ism.

1) A person who shows great independence or individuality in thought or action (Dictionary.com).
2) An advocate of → individualism (Dictionary.com).

→ individual; → -ist.

The particular character, or aggregate of qualities, that distinguishes one person or thing from others (Dictionary.com).

→ individual; → -ity.

The process or state of discriminating the individual from the generic group or species.

→ individualize; → -tion.

To make individual or distinctive; give an individual or distinctive character to (Dictionary.com).

→ individual; → -ize.

Of, relating to, or remaining as a residue; leftover.

→ residue; → -al.

The magnetic field left in an iron core after excitation has been removed.

→ residual; → field.

The principle admitted in → quantum mechanics that all particles have a wave-like nature and that waves have a particle aspect. The wave-particle duality is of fundamental importance in obtaining a realistic picture of the → elementary particles.
See also: → particle nature, → wave nature, → de Broglie hypothesis, → Davisson-Germer experiment.

→ wave; → particle; → duality.