The Collaborative International Dictionary of English v.0.48:

Venal \Ve"nal\ (v[=e]"nal), a. [L. vena a vein.]
   Of or pertaining to veins; venous; as, venal blood. [R.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Venal \Ve"nal\, a. [L. venalis, from venus sale; akin to Gr.
   'w^nos price, Skr. vasna: cf. F. v['e]nal.]
   Capable of being bought or obtained for money or other
   valuable consideration; made matter of trade or barter; held
   for sale; salable; mercenary; purchasable; hireling; as,
   venal services. " Paid court to venal beauties." --Macaulay.
   [1913 Webster]

         The venal cry and prepared vote of a passive senate.
                                                  --Burke.
   [1913 Webster]

   Syn: Mercenary; hireling; vendible.

   Usage: Venal, Mercenary. One is mercenary who is either
          actually a hireling (as, mercenary soldiers, a
          mercenary judge, etc.), or is governed by a sordid
          love of gain; hence, we speak of mercenary motives, a
          mercenary marriage, etc. Venal goes further, and
          supposes either an actual purchase, or a readiness to
          be purchased, which places a person or thing wholly in
          the power of the purchaser; as, a venal press. Brissot
          played ingeniously on the latter word in his
          celebrated saying, " My pen is venal that it may not
          be mercenary," meaning that he wrote books, and sold
          them to the publishers, in order to avoid the
          necessity of being the hireling of any political
          party.
          [1913 Webster]

                Thus needy wits a vile revenue made,
                And verse became a mercenary trade. --Dryden.
          [1913 Webster]

                This verse be thine, my friend, nor thou refuse
                This, from no venal or ungrateful muse. --Pope.
          [1913 Webster]

WordNet (r) 3.0 (2006):

venal
    adj 1: capable of being corrupted; "corruptible judges";
           "dishonest politicians"; "a purchasable senator"; "a
           venal police officer" [syn: corruptible, bribable,
           dishonest, purchasable, venal]

Moby Thesaurus II by Grady Ward, 1.0:

66 Moby Thesaurus words for "venal":
   a hog for, acquisitive, all-devouring, approachable, avaricious,
   avid, bent, bottomless, bribable, bribeable, buyable, corrupt,
   corruptible, coveting, covetous, crooked, devouring, dishonorable,
   esurient, fixable, flagitious, gluttonous, gobbling, grabby,
   grasping, greedy, hack, hireling, hoggish, ignoble, infamous,
   iniquitous, insatiable, insatiate, limitless, mercenary, miserly,
   money-hungry, money-mad, nefarious, omnivorous, on the pad,
   on the take, overgreedy, paid, piggish, purchasable, quenchless,
   rapacious, ravening, ravenous, slakeless, sordid, swinish,
   unappeasable, unappeased, unethical, unprincipled, unquenchable,
   unsated, unsatisfied, unscrupulous, unslakeable, unslaked, vicious,
   voracious



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

VENAL. Something that is bought. The term is generally applied in a bad
sense; as, a venal office is an office which has been purchased.