Overwhelm one good lady with appointment (8)
I believe the answer is:
inundate
'overwhelm' is the definition.
(inundate can mean to overwhelm or overload)
'one good lady with appointment' is the wordplay.
'one' becomes 'i' (Roman numeral).
'good lady' becomes 'nun' (I have seen 'Religious lady ' mean 'nun' so perhaps 'lady' could also mean 'nun'. I am not sure about the 'good' bit.).
'with' is a charade indicator (letters next to each other).
'appointment' becomes 'date' (synonyms).
'i'+'nun'+'date'='INUNDATE'
Can you help me to learn more?
(Other definitions for inundate that I've seen before include "Flood, overwhelm" , "Overwhelm, swamp" , "Overwhelm (as if) with water" , "Flood - and unite (anag)" , "Aunt Enid could engulf badly" .)