The Collaborative International Dictionary of English v.0.48:

Putative \Pu"ta*tive\, a. [L. putativus, fr. putare, putatum, to
   reckon, suppose, adjust, prune, cleanse. See Pure, and cf.
   Amputate, Compute, Dispute, Impute.]
   Commonly thought or deemed; supposed; reputed; as, the
   putative father of a child. "His other putative (I dare not
   say feigned) friends." --E. Hall.
   [1913 Webster]

         Thus things indifferent, being esteemed useful or
         pious, became customary, and then came for reverence
         into a putative and usurped authority.   --Jer. Taylor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

putative
    adj 1: purported; commonly put forth or accepted as true on
           inconclusive grounds; "the foundling's putative father";
           "the putative author of the book"

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "putative":
   accountable, accounted as, alleged, ascribable, assignable,
   assumed, assumptive, attributable, attributed, charged,
   conjectural, conjectured, credited, deemed, derivable from,
   derivational, derivative, due, explicable, given, granted,
   hypothetical, imputable, imputed, inferred, owing, postulated,
   postulational, premised, presumed, presumptive, referable,
   referred to, reputed, supposed, suppositional, supposititious,
   suppositive, suppository, taken for granted, traceable,
   understood



Bouvier's Law Dictionary, Revised 6th Ed (1856):

PUTATIVE. Reputed to be that which is not. The word is frequently used, as
putative father, (q.v.) putative marriage, putative wife, and the like. And
Toullier, tome 7, n. 29, uses the words putative owner, proprietare putatif.
Lord Kames uses the same expression. Princ. of Eq. 391.