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

1) A position of two bodies in the → solar system when they have the same → celestial longitude, seen from the Earth. The bodies can be a → planet and the → Sun, two planets or the → Moon and a planet. The → superior planets are in conjunction with the Sun, when, seen from the Earth, they are right behind the Sun. The → inferior planets, such as Mercury and Venus, have two conjunctions with the Sun: → inferior conjunction, when they are between the Earth and the Sun, and → superior conjunction, when they are on the other side of the Sun.
2) Logic: A → proposition of the form "A and B" (A ∧ B), where A and B are themselves propositions. For example, if A is "It is 8 O'clock" and B is "We are late," then A∧ B is "It is 8 O'clock and we are late." A and B are called → conjuncts. The conjunction of A and B is → true only if A and B are both true.
3) Grammar: A word that connects words, phrases, or clauses, or sentences. Examples are: and, or, but, because, however, neither.

M.E. conjunccio(u)n, from O.Fr. conjonction, from L. conjunctionem, p.p. of conjugare "to join together," from → com- "together" + jugare "to join," from jugum "yoke," from PIE *yeug- "to join;" Av. yaog- "to yoke, put to; to join, unite;" Mid.Pers. jug, ayoxtan "to join, yoke;" Mod.Pers. yuq "yoke," variant juh, → yoke; Skt. yugam "yoke;" Hittite yugan "yoke;" Gk. zygon "yoke," zeugnyanai "to join, unite;" O.C.S. igo; O.Welsh iou; Lith. jungas; O.E. geoc.

Hamistân "standing together," from ham- "together," → com- + istân "standing," from istâdan "to stand" (cf. Skt samstha "an assembly"), Mid.Pers. êstâtan, O.Pers./Av. sta- "to stand, stand still; set," Av. hištaiti, cf. Skt. sthâ- "to stand," Gk. histemi "put, place, weigh," stasis "a standing still," L. stare "to stand."
Hâjuheš, from hâ-, variant of ham-, → com-, + juh "yoke," as above.

The conjunction of an inferior planet with the Sun when the planet is between the Sun and the Earth. → superior conjunction.

→ inferior; → conjunction.

The conjunction of a planet with the Sun which occurs when the planet is beyond the Sun. → inferior conjunction.

→ superior; → conjunction.

A rare event involving a particularly intricate set of movements of two planets or a planet and a star where they meet each other three times in a short period either in opposition or at the time of inferior conjunction, if an inferior planet is involved. The visible movement of the planet or the planets in the sky is therefore normally prograde at the first conjunction, retrograde at the second conjunction and again prograde at the third conjunction.

→ triple; → conjunction.