The Collaborative International Dictionary of English v.0.48:

Inset \In*set"\, v. t.
   To infix. [Obs.] --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Inset \In"set\, n.
   1. That which is inserted or set in; an insertion.
      [1913 Webster]

   2. (Bookbinding) One or more separate leaves inserted in a
      volume before binding; as:
      (a) A portion of the printed sheet in certain sizes of
          books which is cut off before folding, and set into
          the middle of the folded sheet to complete the
          succession of paging; -- also called offcut.
      (b) A page or pages of advertisements inserted.
          [1913 Webster]

WordNet (r) 3.0 (2006):

inset
    n 1: a small picture inserted within the bounds or a larger one
    2: an artifact that is inserted or is to be inserted [syn:
       insert, inset]
    3: a piece of material used to strengthen or enlarge a garment
       [syn: gusset, inset]
    v 1: set or place in