The Collaborative International Dictionary of English v.0.48:

Net \Net\, a. [F. See Neat clean.]
   1. Without spot; pure; shining. [Obs.]
      [1913 Webster]

            Her breast all naked as net ivory.    --Spenser.
      [1913 Webster]

   2. Free from extraneous substances; pure; unadulterated;
      neat; as, net wine, etc. [R.]
      [1913 Webster]

   3. Not including superfluous, incidental, or foreign matter,
      as boxes, coverings, wraps, etc.; free from charges,
      deductions, etc; as, net profit; net income; net weight,
      etc. [Less properly written nett.]
      [1913 Webster]

   Net tonnage (Naut.), the tonnage of a vessel after a
      deduction from the gross tonnage has been made, to allow
      space for crew, machinery, etc.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

nett \nett\ adj.
   remaining after all deductions; same as net a., 3.
   Contrasted to gross. [Brit.] [Narrower terms: take-home]

   Syn: net, clear.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

nett
    adj 1: remaining after all deductions; "net profit" [syn: net,
           nett] [ant: gross]
    v 1: catch with a net; "net a fish" [syn: net, nett]