Regret, ruefulness (7)
I believe the answer is:
remorse
I believe this is a double definition.
'regret' is the first definition.
(remorse is a feeling of regret)
'ruefulness' is the second definition.
(I know that remorse is a type of ruefulness)
(Other definitions for remorse that I've seen before include "Sorrow for wrong committed" , "Regret or sorrow for wrong-doing" , "Sorrow for sin or wrong-doing" , "Pity" , "Distress from a sense of guilt" .)