From WordNet (r) 3.0 (2006) [wn]:
somewhere
adv 1: in or at or to some place; "she must be somewhere";
(`someplace' is used informally for `somewhere') [syn:
somewhere, someplace]
n 1: an indefinite or unknown location; "they moved to somewhere
in Spain"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Somewhere \Some"where`\, adv.
In some place unknown or not specified; in one place or
another. "Somewhere nigh at hand." --Milton.
[1913 Webster]