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

A branch of medicine that deals with the diagnosis, management and treatment of various infectious or contagious diseases.

→ infection; → -logy.

The science and activity of receiving, storing, processing, and transmitting information by using → computers.

→ information; → technology.

A catalog based on a pre-defined list of objects prepared for new observations, mainly using → space telescopes. → Ecliptic Plane Input Catalogue.

→ input; → catalog.

Any of molecular entities which differ in their isotopic composition but retain the same → chemical elements, e.g. H₂O and HDO.

Abbreviation of → isotopic → analogue.

The basic unit of mass in the → International System of Units (SI) and → MKS versions of the → metric system, equal to 1,000 → grams. The kilogram was until 2019 defined as the mass of the standard (international prototype) kilogram, a platinum-iridium cylinder kept at the International Bureau of Weights and Measures (BIPM), at Sèvre, near Paris, France. Copies of this prototype are kept by the standards agencies of all the major industrial nations. A kilogram is equal to the mass of 1,000 cubic cm of water at 4°C (→ maximum density). According to the new (2019) definition, the kilogram is defined by taking the fixed numerical value of the → Planck constant (h) to be 6.62607015 × 10^-34 when expressed in the unit J.s, which is equal to kg m² s^-1, where the meter and the second are defined in terms of c and Δν Cs.

→ kilo-; → gram.

A metric unit of force which is equal to a mass of one kilogram multiplied by the standard acceleration due to gravity on Earth (9.80665 m sec^-2). Therefore one (1) kilogram-force is equal to 1 kg × 9.80665 m sec^-2 = 9.80665 → newtons.

→ kilogram; → force.

An approach in which terms reconstructed in the → proto-language are used to make inferences about its speakers' culture and environment.

→ language;→ paleontology.

A branch of → linguistics that studies the formation, meaning, and use of words and their idiomatic combinations. In contrast to → terminology, lexicology is based on words and does not conceive of meaning unless it is related to the word.

From lexic, from Gk. lexicon, noun use of lexikos "pertaining to words," from lexis "word; speech" (+ -ikos, → -ics), from legein "to say, speak, recount," + -o-, + → -logy.

Vâžešnâsi, from vâžé, → word, + -šenâsi, → -logy.

1) Any of various records, made in rough or finished form, concerning a trip made by a ship or aircraft and dealing with particulars of navigation, weather, engine performance, discipline, and other pertinent details; → logbook.
2) To enter in a log; compile; amass; keep a record of (Dictionary.com).

M.E. logge, variant of lugge "pole, limb of tree; piece of wood," of unknown origin, back formation from logbook, a book used by sailors to record the speed measurements made by means of a chip of a tree log on the end of a reeled log line.

1) Log, loan from E., as above.
2) Logidan, infinitive from log.

Computers: To enter identifying data, as a user name or password, into a database, mobile device, or computer, especially a multi-user computer or a remote or networked system, so as to to access and use it (Dictionary.com).

→ log; → in.

Computers: To terminate a session.

→ log; → out.

The → exponent of the → power to which it is necessary to raise a fixed number to produce the given number. The fixed number is called the → base. The logarithm of x to the base a, denoted log_a(x), is the unique → real number  y such that a^y = x. In the familiar system of → common logarithms, the base is 10. In the system of → natural logarithms, the base is e = 2.7182818 ... (→ number e). For example, the logarithm of 100 (base 10) is 2 because 10² = 100.

Mod.L. logarithmus, coined by Scottish mathematician John Napier (1550-1617), literally "ratio-number," from Gk. logos "proportion, ratio, word," → logic + arithmos "number," → arithmetic.

Of or pertaining to a → logarithm.

→ logarithm; → -ic.

Same as → reddening coefficient.

→ logarithmic; → extinction.

A scale of measurement in which an increase of one unit represents a tenfold increase in the quantity measured (for common logarithms)

→ logarithmic; → scale.

A book in which details of a trip made by a ship or aircraft are recorded; log (Dictionary.com).

→ log; → book.

1) The science that investigates the principles governing correct or reliable inference.
2) The system or principles of reasoning applicable to any branch of knowledge or study.
3) A particular method of reasoning or argumentation.

M.E. logik; O.Fr. logique, from L. (ars) logica, from Gk. logike (techne) "reasoning (art)," from feminine of logikos "pertaining to speaking or reasoning," from logos "reason, idea, word."

Guyik, from guy- present stem of goftan "to say, speak, relate, tell; to compose a poem," from Mid.Pers. guftan "to say, tell, utter;" O.Pers. gaub- "to say" + -ik, → -ic.
Cemguyik, from Mid.Pers. cimgôwâgih "logic," from cim "cause, reason, meaning" (Proto-Iranian *cahmāt "what for;" cf. Skt. kasmāt "why, where from," kim "what") + gôwâgih Mod.Pers. guyi, as above.

A diagram that uses special symbols called logic symbols to represent the detailed functioning of electronic logic circuits. The symbols do not represent the type of electronics used, but only their functions.

→ logic; → diagram.

1) According to or agreeing with the principles of logic.
2) Reasoning in accordance with the principles of logic, as a person or the mind.
3) Of or pertaining to logic (Dictionary.com).

→ logic; → -al.

A symbol that can be combined with one or more → sentences in order to form a new sentence. For example "and" (∧), "or" (∨) "not" (¬), "if-then" (→), and "iff" (⇔).

→ logical; → connective.