Feel remorse having run over bird (6)
I believe the answer is:
Here is my best explanation:
'feel remorse' is the definition.
(I've seen this before)
'run over bird' is the wordplay.
'run' becomes 'r' (cricket abbreviation).
'over' means one lot of letters go next to another.
'bird' becomes 'egret' (egret is a kind of bird).
'having' acts as a link.