The Collaborative International Dictionary of English v.0.48:
Snift \Snift\, v. i. [imp. & p. p. Snifted; p. pr. & vb. n.
   Snifting.] [From Sniff.]
   1. To snort. [Obs.] "Resentment expressed by snifting."
      --Johnson.
      [1913 Webster]
   2. To sniff; to snuff; to smell.
      [1913 Webster]
            It now appears that they were still snifing and
            hankering after their old quarters.   --Landor.
      [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Snifting \Snift"ing\,
   a. & n. from Snift.
   [1913 Webster]
   Snifting valve, a small valve opening into the atmosphere
      from the cylinder or condenser of a steam engine, to allow
      the escape of air when the piston makes a stroke; -- so
      called from the noise made by its action.
      [1913 Webster]