experiencing or accompanied by sleeplessness; "insomniac old people"; "insomniac nights"; "lay sleepless all night"; "twenty watchful, weary, tedious nights"- Shakespeare
a cavity or passage in a tubular organ; "the lumen of the intestine"
a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions
having little or no weight or apparent gravitational pull; light; "floating freely in a weightless condition"; "a baby bat...fluffy and weightless as a moth"; "jackets made of a weightless polyester fabric"
the basic unit of luminous intensity adopted under the Systeme International d'Unites; equal to 1/60 of the luminous intensity per square centimeter of a black body radiating at the temperature of 2,046 degrees Kelvin
examine eggs for freshness by holding them against a light
not clearly understood or expressed; "an obscure turn of phrase"; "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
not drawing attention; "an unnoticeable cigarette burn on the carpet"; "an obscure flaw"
not famous or acclaimed; "an obscure family"; "unsung heroes of the war"
make obscure or unclear; "The distinction was obscured"
make difficult to perceive by sight; "The foliage of the huge tree obscures the view of the lake"
make undecipherable or imperceptible by obscuring or concealing; "a hidden message"; "a veiled threat"
make less visible or unclear; "The stars are obscured by the clouds"