Overwhelm lady with faith during one assignation (8)
I believe the answer is:
inundate
'overwhelm' is the definition.
(inundate can mean to overwhelm or overload)
'during one assignation' is the wordplay.
'during' becomes 'in' (e.g. during February means in February).
'one' becomes 'un' (northern English dialect form of 'one').
'assignation' becomes 'date' (an assigned meeting).
'in'+'un'+'date'='INUNDATE'
'lady with faith' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for inundate that I've seen before include "'Flood, swamp (8)'" , "Flood, cover with water" , "Flood, overwhelm" , "Submerge or cover in water" , "Overwhelm (as if) with water" .)