Source : Webster's Revised Unabridged Dictionary (1913)

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.]

Source : WordNet®

hypo
     n 1: a compound used as a fixing agent in photographic developing
          [syn: {sodium thiosulphate}, {sodium thiosulfate}]
     2: a piston syringe that is fitted with a hypodermic needle for
        giving injections [syn: {hypodermic syringe}, {hypodermic}]