An Etymological Dictionary of Astronomy and Astrophysics

A coherent set of verified facts, propositions, or principles analyzed in their relation to one another and used to explain and predict phenomena, e.g. the → theory of relativity.
The criterion of the scientific status of a theory is its → falsifiability, → refutability, or → testability. See also → hypothesis, → model.

Etymology (EN): From L.L. theoria, from Gk. theoria “contemplation, speculation, a looking at, things looked at,” from theorein “to consider, view, look at,” from theoros “spectator,” from thea “a view” + horan “to see.”

Etymology (PE): Negaré, from negar present stem of negaridan, negaristan “to look, observe;” Mid.Pers. nigeridan, niger-, nikiritan, nikir- “to look, to watch, to notice, to consider;” ultimately from Proto-Iranian *ni-kar-, from *ni- “down, in, into,” → ni- (PIE), + *kar- “to observe, to consider;” cf. Av. kar- “to remember; to impress on memory;” Skt. kal- “to observe, consider,” kalayati “considers, observes;” Mid.Pers. kartan “to establish; to declare; to found,” (h)angârtan “to consider, to bear in mind, to regard as,” us-kâritan “to consider, deliberate, discuss,” sikâl, sigâl “thought;”
Mod.Pers. engâridan, engâštan “to suppose,”
segâl “thought,” segâlidan “to think, to resolve to injure, to deceive.”