The Collaborative International Dictionary of English v.0.48:

Similarly \Sim"i*lar*ly\, adv.
   In a similar manner.
   [1913 Webster]

WordNet (r) 3.0 (2006):

similarly
    adv 1: in like or similar manner; "He was similarly affected";
           "some people have little power to do good, and have
           likewise little strength to resist evil"- Samuel Johnson
           [syn: similarly, likewise]

Moby Thesaurus II by Grady Ward, 1.0:

60 Moby Thesaurus words for "similarly":
   above, additionally, again, all included, also, altogether,
   among other things, and all, and also, and so, as well, au reste,
   beside, besides, beyond, correspondingly, either, else, en plus,
   extra, farther, for lagniappe, further, furthermore, identically,
   in addition, in kind, in like manner, in such wise, in that way,
   inter alia, into the bargain, item, just like that, just so, like,
   like so, like that, like this, likewise, more, moreover,
   on the side, on top of, over, plus, precisely, so, then, therewith,
   this way, this-a-way, thus, thus and so, thus and thus, thusly,
   thuswise, to boot, too, yet