Penitence, n.
Etymology: [F. pénitence, L. paenitentia. See Penitent, and cf. Penance.]
The quality or condition of being penitent; the disposition of a penitent; sorrow for sins or faults; repentance; contrition. "Penitence of his old guilt." Chaucer. Death is deferred, and penitenance has room To mitigate, if not reverse, the doom. Dryden.
Syn. -- Repentance; contrition; compunction.
Shades of meaning
Fernald has no entry of its own for penitence; he lists it under repentance.
Where he writes about it:
One is moved with penitence for wrong-doing. — from repentance
To speak of regret for a fault of our own marks it as slighter than one regarding which we should express penitence. — from repentance
Penitence is transient, and may involve no change of character or conduct. — from repentance