Old rat finally contrite gives speech (5)
I believe the answer is:
orate
'old rat finally contrite gives speech' is the definition.
I can't judge whether this defines the answer.
'old rat finally contrite' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'finally' suggests the final letters.
The final letter of 'contrite' is 'e'.
'o'+'rat'+'e'='ORATE'
Can you help me to learn more?
(Other definitions for orate that I've seen before include "Talk pompously" , "Spout" , "Speak like Cicero?" , "Give a formal address" , "Make a lengthy speech" .)