Old nasty type and earl release gas in public (5)
I believe the answer is:
orate
'old nasty type and earl release gas in public' is the definition.
I can't judge whether this definition defines the answer.
'old nasty type and earl' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'nasty type' becomes 'rat' (I am not sure about this - if you are sure you should believe this answer much more).
'and' is a charade indicator (letters next to each other).
'earl' becomes 'e'.
'o'+'rat'+'e'='ORATE'
Can you help me to learn more?
(Other definitions for orate that I've seen before include "Speak publicly" , "Speak pompously and at length" , "Pontificate" , "Make a flowery speech" , "Speak formally" .)