The Collaborative International Dictionary of English v.0.48:

Purely \Pure"ly\, adv.
   1. In a pure manner (in any sense of the adjective).
      [1913 Webster]

   2. Nicely; prettily. [Archaic] --Halliwell.
      [1913 Webster]

WordNet (r) 3.0 (2006):

purely
    adv 1: restricted to something; "we talked strictly business"
           [syn: strictly, purely]

Moby Thesaurus II by Grady Ward, 1.0:

120 Moby Thesaurus words for "purely":
   a outrance, absolutely, after a fashion, all, all in all, all out,
   alone, altogether, appreciably, at any rate, at best, at least,
   at most, at the least, at the most, at the outside, at worst,
   barely, beyond all bounds, beyond compare, beyond comparison,
   beyond measure, blamelessly, clean, cleanly, comparatively,
   completely, conscientiously, dead, decently, detectably, downright,
   entirely, erectly, essentially, exactly, exclusively, extremely,
   fairly, fastidiously, faultlessly, flat out, flawlessly, fully,
   fundamentally, high-mindedly, honestly, honorably, ideally,
   immaculately, immeasurably, impeccably, in, in a manner, in a way,
   in part, in some measure, in the extreme, incalculably,
   incompletely, indefinitely, infallibly, infinitely, integrally,
   irreducibly, irreproachably, just, just right, leastwise, merely,
   meticulously, mildly, moderately, modestly, morally, most, nobly,
   not comprehensively, not exhaustively, only, part, partially,
   partly, perfectly, plainly, pro tanto, punctiliously, radically,
   relatively, reputably, righteously, scrupulously, simply,
   simply and solely, singly, so far, solely, somewhat, spotlessly,
   stainlessly, thoroughly, thus far, to a degree, to some degree,
   tolerably, totally, unanalyzably, unconditionally, undividedly,
   unequivocally, unimpeachably, unspottedly, uprightly, upstandingly,
   utterly, virtuously, visibly, wholly, with a vengeance, worthily