The Collaborative International Dictionary of English v.0.48:

Stratified \Strat"i*fied\, a.
   Having its substance arranged in strata, or layers; as,
   stratified rock.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Stratify \Strat"i*fy\, v. t. [imp. & p. p. Stratified; p. pr.
   & vb. n. Stratifying.] [Stratum + -fy: cf. F. stratifier.]
   To form or deposit in strata, or layers, as substances in the
   earth; to arrange in strata.
   [1913 Webster] Stratigraphic

WordNet (r) 3.0 (2006):

stratified
    adj 1: arranged in a sequence of grades or ranks; "stratified
           areas of the distribution" [syn: graded, ranked,
           stratified]
    2: deposited or arranged in horizontal layers; "stratified rock"
       [syn: stratified, bedded] [ant: unstratified]
    3: (used of society) socially hierarchical; "American society is
       becoming increasingly stratified" [syn: class-conscious,
       stratified]

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "stratified":
   assorted, cataloged, classified, filed, filmy, foliaceous,
   foliated, graded, grouped, hierarchic, in layers, indexed,
   lamellar, lamellate, lamellated, lamelliform, laminate, laminated,
   laminous, leaflike, leafy, membranous, on file, pigeonholed,
   placed, pyramidal, ranked, rated, scummy, sorted, spathic,
   spathose, stratiform, tabular, three-ply, two-ply