The Collaborative International Dictionary of English v.0.48:

Namely \Name"ly\, adv.
   1. By name; by particular mention; specifically; especially;
      expressly. [Obs.] --Chaucer.
      [1913 Webster]

            The solitariness of man . . . God hath namely and
            principally ordered to prevent by marriage.
                                                  --Milton.
      [1913 Webster]

   2. That is to say; to wit; videlicet; -- introducing a
      particular or specific designation.
      [1913 Webster]

            For the excellency of the soul, namely, its power of
            divining dreams; that several such divinations have
            been made, none can question.         --Addison.
      [1913 Webster]

WordNet (r) 3.0 (2006):

namely
    adv 1: as follows [syn: namely, viz., that is to say, to
           wit, videlicet]

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "namely":
   as here defined, as here interpreted, especially, exempli gratia,
   for example, for instance, id est, in explanation, in other words,
   nominally, particularly, sc, scil, scilicet, specially,
   specifically, that is, to explain, to wit, videlicet, viz