a compound used as a fixing agent in photographic developing
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a piston syringe that is fitted with a hypodermic needle for giving injections
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Hypo \Hy"po\, n. Hypochondria. [Colloq.]
Hypo \Hy"po\, n. [Abbrev. from hyposulphite.] (Photog.) Sodium hyposulphite, or thiosulphate, a solution of which is used as a bath to wash out the unchanged silver salts in a picture. [Colloq.]