Source : Webster's Revised Unabridged Dictionary (1913)

Alleviative \Al*le"vi*a*tive\, a.
   Tending to alleviate. -- n. That which alleviates.

Source : WordNet®

alleviative
     adj : moderating pain or sorrow by making it easier to bear [syn:
           {alleviatory}, {lenitive}, {mitigative}, {mitigatory},
           {palliative}]