1) The layer of rocky → debris and
→ dust that forms the uppermost surface of
→ planets, → natural satellites,
and → asteroids. Regolith on Earth is a product of
From Gk. regho(s) "rug, blanket" + -lith, from lithos "stone."
1) pasraft (#); 2) vâyâzi (#), vâyâzeš (#)
1) Astro.: → retrograde motion.
From L. regression-, from regress-, stem of regredi "to go back," from → re- "back" + gradi "to step, walk."
1) → retrograde.
Fr.: analyse de régression
A statistical technique used to determine the values of parameters for a function that best fits a given set of data.
hamgar-e vâyâzeš (#)
Fr.: coefficient de régression
The slope of the straight line that most closely relates two correlated variables.
Fr.: courbe de régression
A curve representing a non-linear relationship between two or more → variables.
Fr.: équation de régression
A mathematical expression that describes the relationship between two or more variables. It indicates the nature of the relationship and, in particular, the extent to which one can predict some variables by knowing others.
Fr.: fonction de régression
A mathematical function that describes the relationship between two or more variables in a set of data.
Fr.: droite de régression
regression of the nodes
pasraft-e gerehhâ , ~ gowzahrhâ
Fr.: régression des noeuds
The slow motion of the → nodes of the Moon's orbit in the opposite direction to the Moon's movement. This westward motion, caused by perturbations of other bodies, mainly the Earth and Sun, has a rate of 19.35 degrees per year, making one rotation in 18.6 years.
1) bâsâmân (#); 2) razan-mand
Fr.: ordonné, régulier
1) Evenly or uniformly arranged in space or time; orderly; well-ordered.
M.E. reguler, from M.Fr., from O.Fr. reguler, from L.L. regularis "continuing rules for guidance," from L. regula "rule," cognate with Pers. râst, → right.
1) Bâsâmân, from bâ- "with, having" (→ hypo- +
sâmân "order, arrangement,
disposition; boundary, limit," Lârestâni sâmon "sign or mark separating one field from
another," Gilaki, Tabari šalmân "a straight peace of wood or beam, post;"
Mid.Pers. sâmânak, sahmân "limit;" loaned into Arm. sahmân; cf. Skt.
sīmān-, sīmā- "boundary, border, limit."
Fr.: fonction régulière
A function of a complex variable which is single-valued in a domain and which has a finite derivative at every point.
Fr.: galaxie régulière
A galaxy which has a uniformly arranged, symmetrical morphology such as a spiral or elliptical galaxy. Opposite of → irregular galaxy.
Fr.: réflexion régulière
bandevâr-e bâsâmân, mâh-e ~
Fr.: satellite régulier
A satellite that revolves around its planet in an equatorial orbit of low or moderate eccentricity close to the planet. One example of a regular satellite system is the Galilean satellites of Jupiter.
To control, direct, or adjust by a rule, principle, method, etc.
From L.L. regulatus, p.p. of regulare "to control by rule, direct," from L. regula, cognate with Pers. râst→ right.
Razanidan, verbal form of razan, → rule, cognate with L. regula.
Fr.: régulé, réglementé
Controlled or governed according to a rule or principle or law.
Past participle of → regulate.
1) The act of regulating; the state of being regulated.
Verbal noun of → regulate.
A person or thing that regulates.
Agent noun of → regulate.
Regulus (α Leonis)
The brightest star in the constellation → Leo (V = 1.35). Regulus is approximately 77.5 light-years from Earth. It is a triple star system composed of a hot, bluish-white star with a pair of small, faint companions. The main star (Regulus A) is a main sequence of type B7, with a luminosity 140 times brighter than the Sun. Its equatorial rotation speed being 317 kilometers per second, the fast rotation distorts Regulus into an oblate spheroid with an equatorial diameter about 30 percent larger than the polar diameter. As a result, the poles, with a temperature of 15,400 Kelvin, are much hotter than the equator, which glows at 10,200 Kelvin.
L., literally "little king," diminutive of rex "king," related to regere "to keep straight, guide, lead, rule," from PIE base *reg- "to rule, to lead straight, to put right;" akin to Pers. râst "right, straight, correct," → right.
Širdel, literally "the Lion's heart,"
on the model of Ar. Qalb al-Asad (
1) The act or process of reionizing a gas; an instance of this action.