The French start Monday with something juicy (5)
I believe the answer is:
lemon
'something juicy' is the definition.
I can't judge whether this definition defines the answer.
'the french start monday' is the wordplay.
'the french' becomes 'les' (les is the in french).
'start' means to remove the last letter (I've seen 'starts' mean this).
'monday' becomes 'mon' (synonyms).
'les' with its last letter removed is 'le'.
'le'+'mon'='LEMON'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for lemon that I've seen before include "Fruit (which is proverbially "the answer")" , "leaving bitter taste?" , "failure" , "stinker" , "something defective" .)