Single out the French in hot water (6)
I believe the answer is:
pickle
'hot water' is the definition.
(thesaurus)
'single out the french' is the wordplay.
'single out' becomes 'pick' (I can't explain this - if you can you should believe this answer much more).
'the french' becomes 'le' ('the' in French).
'pick'+'le'='PICKLE'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for pickle that I've seen before include "A preserved vegetable or a fine mess" , "Chutney, relish, salsa etc" , "Veg or fruit relish" , "Condiment - tricky situation - troublesome child" , "Relish for cheese" .)