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

Not limited by conditions; absolute.

→ un-; → conditional.

Not awake and aware; not responding to one's environment.

→ non-; → conscious.

The → state of being → unconscious.

→ unconscious; → -ness.

A dune on a planetary surface, used in plural form undae.

From L. unda "wave," cognate with → water.

Šen-tal, from šen "sand" + tal "hill, heap."

A prefixal use of under, as to indicate place or situation below or beneath. Contrary to → over-.

M.E., from O.E. (cf. O.H.G. untar, Ger. unter, Goth. undar), from PIE *ndhero- "lower;" cf. Av. aδara- (adj.), aδairi- (prep.) "below;" Mid.Pers. êr "below, down; low, under," adar "low," azêr "below, under" (Mod.Pers. zir "below, down"); Skt. ádhara- "lower;" O.E. under "under, among").

Kam- "little, few; deficient, wanting; scarce" (Mid.Pers. kam "little, small, few," O.Pers./Av. kamna- "small, few").

The abundance of a chemical element being lower than a reference value, in particular compared to that of the Sun.

→ under-; → abundance.

The behavior of a damped system when the amount of damping is weak so that the system oscillates with the amplitude gradually decreasing to zero. → overdamping.

→ under-; → damping.

1) To estimate at too low a value, rate, or the like.
2) An estimate that is too low. → overestimate.

→ under-; → estimate

Insufficiently qualified for a particular job (OxfordDictionaries.com).

→ under-; → qualified.

The circumstance in which there are not enough pixels in a star's image. The number of pixels that make up a star's image is determined by the relationship between the telescope focal length, the physical size of the pixels, and the size of the star's image. With an undersampled image it is not possible to obtain accurate estimates of the star's image size or its position. Undersampling occurs when the atmospheric seeing conditions are exceptionally good and the pixel size not small enough.

→ under-; → sampling.

To perceive the meaning of.

M.E. understanden, understonden, O.E. understandan "comprehend, grasp the idea of," probably literally "to stand in the midst of," from → under- + standan "to stand," cognate with Pers. istâdan, → standard.

Fahmidan, from Ar. fahm + infinitive suffix -idan.

The ability to understand something; the → power of → abstract  → thought.

→ understand; → -ing.

1) Not definitely or authoritatively decided or settled.
2) Not known.

→ un-; → determined.

A type of meteorite in which the constituting materials (stone, glass, metal) are mixed together in a disorderly mass, in contrast to → differentiated meteorites.

→ un-; → differentiated meteorite.

A wave; the motion of waves.
A wavelike motion in any medium.

From L.L. undulatus "wavy, undulated," from undula "wavelet," diminutive of L. unda "wave."

Mowješ, verbal noun of mowjidan "to undulate," from mowj→ wave.

A prefix with the meaning of "one" occurring in loanwords from L., such as → uniform, → uniaxial, → universe, etc.

From uni- a combining form meaning "one," from L. uni-, from unus, → one;

Yek-, from yek, → one.

Crystal with double refraction possessing only one → optic axis.

→ uni-; axial adj. from → axis; → crystal.

The attribute of someone or something whose identity is not established. → unidentified flying object; → unidentified line.

→ un-; → identify.

Any flying object or phenomenon that cannot be identified by the observer.

→ unidentified; fly; M.E. flien; O.E. fleogan (cf. O.H.G. fliogan, O.N. flügja, M.Du. vlieghen, Ger. fliegen); → object.

A no longer in general use name for → Aromatic Infrared Band.

→ unidentified; → infrared; → band.