The Collaborative International Dictionary of English v.0.48:

Severally \Sev"er*al*ly\, adv.
   Separately; distinctly; apart from others; individually.
   [1913 Webster]

         There must be an auditor to check and revise each
         severally by itself.                     --De Quincey.
   [1913 Webster]

WordNet (r) 3.0 (2006):

severally
    adv 1: apart from others; "the clothes were hung severally"
           [syn: independently, severally]
    2: apart from others; "taken individually, the rooms were, in
       fact, square"; "the fine points are treated singly" [syn:
       individually, separately, singly, severally, one by
       one, on an individual basis]
    3: in the order given; "the brothers were called Felix and Max,
       respectively" [syn: respectively, severally]

Moby Thesaurus II by Grady Ward, 1.0:

43 Moby Thesaurus words for "severally":
   adrift, alone, apart, apart from, apiece, aside from, asunder,
   away from, by itself, distributively, diversely, each,
   each to each, even stephen, exclusively, fifty-fifty,
   half-and-half, in equal shares, in proportion, in the abstract,
   in the singular, in twain, in two, independently, individually,
   manifoldly, multifariously, once, one by one, particularly,
   per annum, per capita, per se, piecemeal, pro rata,
   proportionately, respectively, separately, single-handedly, singly,
   singularly, sundrily, variously