My stoicism is nothing more than spiritual intuition (9)
I believe the answer is:
mysticism
'my stoicism is nothing more' is the definition.
I can't judge whether this defines the answer.
'spiritual intuition' is the wordplay.
'spiritual' becomes 'mystic' (I've seen this before).
'intuition' becomes 'ism' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mystic'+'ism'='MYSTICISM'
'than' acts as a link.
Can you help me to learn more?
(Another definition for mysticism that I've seen is " Vague belief".)