I slept with ten cooks, which is likely to lead to infectious disease (9)
I believe the answer is:
pestilent
'i slept with ten cooks which is likely to lead to infectious disease' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I don't see?
'i slept with ten cooks' is the wordplay.
'with' is a charade indicator (letters next to each other).
'cooks' indicates anagramming the letters.
'i'+'slept'+'ten'='isleptten'
'isleptten' anagrammed gives 'PESTILENT'.
Can you help me to learn more?
(Other definitions for pestilent that I've seen before include "Likely to spread epidemic disease" , "Annoying" , "I lent pets that were noxious" , "Pernicious" , "Plaguey" .)