1. 
2. 
[syn: artificially, unnaturally, by artificial means]
3.  in a manner at variance with what is natural or normal; 
- Example: "The early Church not unnaturally adopted the position that failure to see the messianic character of his work was really caused by the people's own blindness"
The Collaborative International Dictionary of English v.0.48:
Unnatural \Un*nat"u*ral\ (?; 135), a.
   Not natural; contrary, or not conforming, to the order of
   nature; being without natural traits; as, unnatural crimes.
   [1913 Webster]
   Syn: See Factitious.
        [1913 Webster] -- Un*nat"u*ral*ly, adv. --
        Un*nat"u*ral*ness, n.
        [1913 Webster]
WordNet (r) 3.0 (2006):
unnaturally
    adv 1: in an unnatural way; "his other arm lay across his chest,
           unnaturally, as if placed there deliberately, for a
           purpose" [ant: naturally]
    2: not according to nature; not by natural means; "artificially
       induced conditions" [syn: artificially, unnaturally, by
       artificial means] [ant: naturally]
    3: in a manner at variance with what is natural or normal; "The
       early Church not unnaturally adopted the position that
       failure to see the messianic character of his work was really
       caused by the people's own blindness" [ant: course,
       naturally, of course]