The Collaborative International Dictionary of English v.0.48:

Torricellian \Tor`ri*cel"li*an\, a.
   Of or pertaining to Torricelli, an Italian philosopher and
   mathematician, who, in 1643, discovered that the rise of a
   liquid in a tube, as in the barometer, is due to atmospheric
   pressure. See Barometer.
   [1913 Webster]

   Torricellian tube, a glass tube thirty or more inches in
      length, open at the lower end and hermetically sealed at
      the upper, such as is used in the barometer.

   Torricellian vacuum (Physics), a vacuum produced by filling
      with a fluid, as mercury, a tube hermetically closed at
      one end, and, after immersing the other end in a vessel of
      the same fluid, allowing the inclosed fluid to descend
      till it is counterbalanced by the pressure of the
      atmosphere, as in the barometer. --Hutton.
      [1913 Webster]