mis·e·re·re 
(mĭz′ə-rârē, -rîrē)
(mĭz′ə-rârē, -rîrē)n.
1. Miserere
a. The 51st Psalm.
b. A musical setting of this psalm.
2.
a. A prayer for mercy.
b. An expression of lamentation or complaint.
3. See misericord.
[Latin miserēre, have mercy, the first word of the psalm, imperative sing. of miserērī, to feel pity, from miser, wretched.]