The Collaborative International Dictionary of English v.0.48:

Unattended \Unattended\
   See attended.

WordNet (r) 3.0 (2006):

unattended
    adj 1: not watched; "she dashed out leaving the bar unattended";
           "a fire left unattended"
    2: lacking accompaniment or a guard or escort; "unattended
       women"; "problems unattended with danger"
    3: lacking a caretaker; "a neglected child"; "many casualties
       were lying unattended" [syn: neglected, unattended]

Moby Thesaurus II by Grady Ward, 1.0:

92 Moby Thesaurus words for "unattended":
   abandoned, alienated, alone, aloof, apart, asunder, bare-handed,
   bipartite, companionless, defenseless, deserted, detached,
   dichotomous, discontinuous, discrete, disregarded, distinct,
   divergent, friendless, guardless, half-done, helpless, homeless,
   ignored, in two, incoherent, insular, isolated, kithless,
   laid aside, left undone, lone, lonely, lonesome, missed, neglected,
   noncohesive, omitted, overlooked, partitioned, passed by,
   passed over, passed up, pigeonholed, put aside, removed, rootless,
   separate, separated, shunted, sidelined, sidetracked,
   single-handed, slighted, solitary, solo, unabetted, unaccompanied,
   unaided, unarmed, unarmored, unasked, unassisted, unassociated,
   unattached, unattended to, uncared-for, unchaperoned, unconnected,
   unconsidered, uncovered, undefended, undone, unescorted,
   unfortified, ungarrisoned, unguarded, unjoined, unprotected,
   unregarded, unscreened, unseconded, unsheltered, unshielded,
   unsolicited, unsupported, unsuspecting, untended, unwarned,
   unwatched, weaponless, withdrawn