Fr.: point d'Arago
Named for François Arago (1786-1853), French physicist; → point
1) Based on individual will or choice rather than by reason or necessity.
M.E., from O.Fr. arbitraire or directly from L. arbitrarius "depending on the will, uncertain," from → ad- "to" + baetere "to come, go."
Fr.: constante arbitraire
A constant quantity in → equations which takes various values but which remains unaffected by the changes in the values of the → variables of the equation. Most → differential equations have more than one → solution. In general, the number of arbitrary constants of an ordinary differential equation is given by the → order of the highest → derivative.
1) In → graph theory, a → rooted tree
that has a natural orientation in which all → paths
are directed away from the → root. More specifically, a
→ directed graph in
which, for a → vertex u, called the
→ root, and any other vertex v,
there is exactly one → directed path
from u to v.
Šâkedâri, nous from šâkedâr, → arborescent.
Having the shape or characteristics of a tree in growth, structure, or appearance.
From Fr. arborescent, from L. arborescent-, p.p. of arborescere "to grow into a tree," from arbor, arboris "tree."
1) General: Something shaped like a → curve
or → arch.
M.E. ark, from M.Fr. arc "bow," from L. arcus "bow, arch" (cf. Goth. arhwazna "arrow," O.E. earh), PIE *arqu- "bowed, curved."
Kamân "arc, bow" from Mid.Pers. kamân, related to xam "curve," cf. Breton kamm "curved, bent," Gk. kampe "a corner, a joint," L. campus "a field," Lith. kampus "corner," PIE *kamb- "to bend, crook."
kamân-daqiqé, daqiqe-ye kamâni
Fr.: minute de degré
A unit of angular size equal to 1/60 of a degree.
arc of light
Fr.: arc de lumière
arc of separation
Fr.: arc de séparation
arc of vision
Fr.: arc de vision
kamân-sâniyé, sâniye-ye kamâni
Fr.: seconde de degré
A unit of angular size equal to 1/3.600 of a degree.
Fr.: spectre d'étincelle
The spectrum produced by an atom or mixture of atoms as a result of vaporization within an electric arc generated between two electrodes.
1) A curved structure, normally in the vertical plane, that spans an opening.
M.E. arch(e), from O.Fr. arche "arch of a bridge," from L. arcus "a bow," → arc.
Taq "arch," from tâk, contraction of târak, → vertex.
arch of foot
Fr.: arche du pied
Any of the four vaulted structures in the foot: the internal (medial) longitudinal, the outer (lateral) longitudinal, and two transverse (Medical Dictionary, Farlex).
The study that deals with the astronomical knowledge of prehistoric peoples (season events, calendars, observing sites, astronomical alignments) and its influence on their cultures and societies (mythologies, religions, life). Archaeoastronomy covers the intersection between astronomy and archaeology. Same as → astroarchaeology, megalithic astronomy.
Archeoastronomy, from L. archaeo-, archeo "ancient; earlier; primitive," from Gk. arkhaio-, from arkhaios "ancient" + → astronomy.
Bâstânaxtaršenâsi, from bâstân "ancient" + axtaršenâsi, → astronomy.
Fr.: arché-, archi
A prefix meaning "principal, prior, original, first, early" Same as archi-. → archetype.
From Gk. arkhe-, from arckhon "ruler," noun use of p.p. of arkhein "to rule."
Sar-, from sar "top, summit, the capital of a pillar," → head.
Fr.: amas des Arches
One of the three → Galactic center clusters supposed to be the densest young → massive star cluster in the Milky Way. It contains the richest collection of → O stars and → WN Wolf-Rayet stars in any cluster in the Galaxy, thus representing the largest collection of the most massive stars in the Galaxy. With its estimated age of 2-3 million years, the Arches cluster is the youngest of the massive clusters in the Galactic center. → Quintuplet cluster; → Central cluster (Figer et al. 2002, ApJ 581, 258; and 1999, ApJ 525, 750).
Arches, from the presence of Galactic center thermal → arched filaments, about 100 → light-years in projection from the Galactic center (Morris & Yusef-Zadeh, 1985, AJ 90, 2511), from M.E. arche, O.Fr. arche "arch of a bridge," from L. arcus, → arc; → cluster.
The original pattern or model from which all things of the same kind are copied or on which they are based; a model or first form; prototype (Dictionary.com).
Fr.: principe d'Archimède
A body immersed totally or partially in a liquid is buoyed up by a force equal to the weight of the liquid displaced by the body. → buoyancy.
Archimedes of Syracuse (c. 287 BC - c. 212 BC), Greek mathematician and inventor; → principle.
Arašmidos altered form of Archimedes in classical Ar. texts; parvaz, → principle.
1) The art or practice of designing and building structures.
M.E., from M.Fr. architecture, from L. architectura, from architectus "architect," from Gk. arkhitekton "master builder, director of works," from arkhi- "chief" + tekton "builder, carpenter," → technique.
Mehrâzik, from mehrâz literally "chief mason," from meh- "great, large," → high, + râz "mason, builder" (Borhân-e Qâte'), from Mid.Pers. râz "builder, architect," probably related to O.Pers. râs-, Av. râz- "to direct, set, put in line" (with many cognates in Pers., such as râst "straight, direct, true;" raj, rak, râk, rezg (Lori), radé, râdé "line, rule, row," rasté, râsté "row, a market with regular ranges of shops;" ris, risé "straight"); cf. Skt. raj- "to direct, stretch," rjuyant- "walking straight;" Gk. orektos "stretched out;" L. regere "to lead straight, guide, rule," p.p. rectus "right, straight;" Ger. recht; E. right; PIE base *reg- "move in a straight line," hence, "to direct, rule;" + -ik, → -ics.