obscure (adj.)

c. 1400, "dark," figuratively "morally unenlightened; gloomy," from Old French obscur, oscur "dark, clouded, gloomy; dim, not clear" (12c.) and directly from Latin obscurus "dark, dusky, shady," figuratively "unknown; unintelligible; hard to discern; from insignificant ancestors," from ob "over" (see ob-) + -scurus "covered," from PIE root *(s)keu- "to cover, conceal." Related: Obscurely.

The figurative sense of "not readily understood, not manifest to the mind or understanding" is from early 15c.; of persons, "not illustrious or noted, unknown to fame," 1540s. The more literal sense of "indistinct, without clearness of form or outline, hardly perceptible, not capable of being clearly seen through lack of light" is attested in English from 1590s.

In regard to the meaning of something said or written, obscure is general, being founded upon the figure of light which is insufficient to enable one to see with any clearness; this figure is still felt in all the uses of the word. [Century Dictionary, 1895]

obscure (v.)

early 15c., obscuren, "to cover (something), cloud over," from obscure (adj.) or else from Old French obscurer, from Latin obscurare "to make dark, darken, obscure," from obscurus. Meaning "to conceal from knowledge or observation, disguise" is from 1520s; that of "to overshadow or outshine" is from 1540s. Related: Obscured; obscuring.

Definitions of obscure
obscure (adj.)
remote and separate physically or socially; "preserved because they inhabited a place apart"- W.H.Hudson;
an obscure village
Synonyms: apart / isolated
obscure (adj.)
not clearly expressed or understood; "an impulse to go off and fight certain obscure battles of his own spirit"-Anatole Broyard; "their descriptions of human behavior become vague, dull, and unclear"- P.A.Sorokin; "vague...forms of speech...have so long passed for mysteries of science"- John Locke;
an obscure turn of phrase
Synonyms: vague
obscure (adj.)
marked by difficulty of style or expression;
those who do not appreciate Kafka's work say his style is obscure
Synonyms: dark
obscure (adj.)
difficult to find;
an obscure retreat
Synonyms: hidden
obscure (adj.)
not famous or acclaimed;
an obscure family
Synonyms: unknown / unsung
obscure (adj.)
not drawing attention;
an obscure flaw
Synonyms: unnoticeable
obscure (v.)
make less visible or unclear;
The stars are obscured by the clouds
the big elm tree obscures our view of the valley
Synonyms: befog / becloud / obnubilate / haze over / fog / cloud / mist
obscure (v.)
make unclear, indistinct, or blurred;
Synonyms: confuse / blur / obnubilate
obscure (v.)
make obscure or unclear;
The distinction was obscured
Synonyms: bedim / overcloud
obscure (v.)
reduce a vowel to a neutral one, such as a schwa;
obscure (v.)
make undecipherable or imperceptible by obscuring or concealing;
Synonyms: blot out / obliterate / veil / hide