The Collaborative International Dictionary of English v.0.48:

Soft-hearted \Soft"-heart`ed\, a.
   Having softness or tenderness of heart; susceptible of pity
   or other kindly affection; gentle; meek. --
   Soft"-heart`ed*ness, n.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "softhearted":
   Christian, Christlike, Christly, affectionate, benign, benignant,
   bleeding, brotherly, charitable, clement, commiserative,
   compassionate, condolent, decent, delicate, emotionable,
   forbearant, fraternal, gentle, good, gracious, human, humane,
   impressionable, kind, kindhearted, kindly, kindly-disposed,
   lenient, loving, melting, merciful, nice, passible, pitying,
   receptive, responsive, ruthful, sensible, sensitive, soft,
   susceptible, sympathetic, sympathizing, tender, tenderhearted,
   understanding, warm, warmhearted