(astronomy, obsolete) a nebula that appears white in colouration through a high-powered telescope (nebulae often appear to have some hint of colour through a powerful telescope, but white when not ...

(chemistry) A notation for denoting the prevalence of an isotope, equal to the normalized ratio of one isotope to another in a sample relative to that same ratio in a standard.

plural of taper candle

(US) A member of the United States Cabinet who stays at a physically distant, secure, and undisclosed location when the President, the vice president, and the other officials in the line of success...