The rabble may take sick leave for vacation (8)
I believe the answer is:
canaille
'the rabble' is the definition.
(I have seen 'French rabble' mean 'canaille' so perhaps 'rabble' could also mean 'canaille')
'may take sick leave for vacation' is the wordplay.
I cannot quite see how this works, but
'may' could be 'can' (synonyms) and 'can' is present in the answer.
'sick' could be 'ill' (similar in meaning) and 'ill' is found within the answer.
The remaining letters 'ae' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for canaille that I've seen before include "Alliance with French rabble or dogs" , "Nail lace up for the French mob" , "Vulgar rabble" .)