From WordNet (r) 2.0 (August 2003) [wn]:
pieta
n : a representation of the Virgin Mary mourning over the dead
body of Jesus
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Pieta \Pi*e*t[`a]"\ (p[-e]*[asl]*t[aum]"), n. [It.] (Fine Arts)
A representation of the dead Christ, attended by the Virgin
Mary or by holy women and angels. --Mollett.
[1913 Webster]