methylene blue

American  

noun

Chemistry, Pharmacology.

1. a dark-green, crystalline compound, C 1 6 H 1 8 ClN 3 S, that dissolves in water to form a deep-blue solution: used chiefly as a dye, as a bacteriological and biological stain, and as an antidote for cyanide poisoning.

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methylene blue British  

noun

1. Also called: methylthionine chloride.  a dark-green crystalline compound forming a blue aqueous solution, used as a mild antiseptic and biological stain. Formula: C 16 H 18 N 3 SCl.3H 2 O

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methylene blue Scientific  

1. A basic dye that forms a deep blue solution when dissolved in water. It is used as an antidote for cyanide poisoning and as a bacteriological stain. Chemical formula: C ₁₆ H ₁₈ N ₃ SCl.

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Etymology

Origin of methylene blue

First recorded in 1885–90