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.
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.