The Collaborative International Dictionary of English v.0.48:

Impanel \Im*pan"el\, v. t. [imp. & p. p. Impaneledor
   Impanelled; p. pr. & vb. n. Impaneling or Impanelling.]
   [Pref. im- in + panel. Cf. Empanel.] [Written also
   empanel.]
   To enter in a list, or on a piece of parchment, called a
   panel; to form or enroll, as a list of jurors in a court of
   justice. --Blackstone.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Empanel \Em*pan"el\, n. [Pref. em- (L. in) + panel.] (Law)
   A list of jurors; a panel. [Obs.] --Cowell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Empanel \Em*pan"el\, v. t.
   See Impanel.
   [1913 Webster]

WordNet (r) 3.0 (2006):

empanel
    v 1: enter into a list of prospective jurors [syn: empanel,
         impanel]
    2: select from a list; "empanel prospective jurors" [syn:
       empanel, impanel, panel]