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

To press together; force into less space.

From O.Fr. compresser, from L. compressare "to press together," from comprimere "to squeeze," from → com- "together" + premere "to press;" PIE *prem-/*pres- "to strike."

Tanjidan "to squeeze, press, pull together," related to tang "tight," also "horse girth, a strap for fastening a load" (Mid.Pers. tang "tight, narrow"); cf. Skt. tanákti "draws together, contracts;" cognate with E. → tight; cp. Skt. tanákti "draws together, contracts;" M.H.G. dihte "dense, thick;" Ger. dicht "dense, tight;" O.H.G. gidigan; Ger. gediegen "genuine, solid, worthy;" PIE *tenk- "to thicken, clot; thick, solid."

Pressed into less space; condensed.

Past participle of → compress.

Air whose density is increased by being subjected to a pressure greater than atmospheric pressure.

→ compressed; → air.

The ability or quality to be reduced in volume. The coefficient of compressibility of a substance is given by c = (1/V).(δV/δp), where δV is the change in the volume resulting from a change of pressure δp, the temperature remaining constant.

Noun from → compressible.

Able to be reduced in volume. → compressible flow.

Adjective from → compress + -ible, variant of -able.

Tanjidani, tanješpazir from tanjidan, → compress, + adjective suffix -i; tanješpazir from tanješ, → compression, + pazir "receiving, admitting; having, endowed with;" → -able.

A flow in which changes of the density, induced by velocities and their fluctuations, are not negligible.

→ compressible; → flow.

The act or process of compressing; the state of being compressed.

Verbal noun from → compress.

In thermodynamics, the quantity Z = pV_m/RT, in which P is the gas pressure, V_m the molar volume, R the gas constant, and T the temperature. The compression factor is a measure of the deviation of a real gas from an ideal gas. For an ideal gas the compression factor is equal to 1.

→ compression; → facteur.

A → longitudinal wave that compresses the → medium along the direction of → propagation, such as a → sound wave. Same as → compressional wave.

→ compression; → wave.

Of or relating to → compression.

→ compression; → -al.

An → elastic wave that travels through a → medium with the particles of the medium moving in the same direction as the wave propagation. The compressional wave is the wave that is primarily used in → seismic exploration. Also called P-wave, primary wave, pressure wave.

→ compressional; → wave.

To cause to undergo → decompression.

→ de- + → compress.

1) A gradual decrease in surrounding → pressure, especially the controlled decrease in pressure that divers undergo after working in deep water or breathing compressed air.
2) Computers: The restoration of compressed electronic data to their full size.

→ de- + → compression.

A flow whose volume or density does not change under pressure, and therefore its density is a constant. In other words, an ideal flow in which the → divergence of velocity is zero. → compressible flow.

→ incompressible, from → in "not" + → compressible; → flow.