Fit singular form of Buddhist mystical text, you might think (7)
I believe the answer is:
tantrum
'fit' is the definition.
(I know that fit can be written as tantrum)
'singular form of buddhist mystical text you might think' is the wordplay.
I cannot really understand how this works, but
'singular' could be 'rum' (synonyms) and 'rum' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tantrum that I've seen before include "Uncontrolled outburst of anger" , "Fit - pet" , "Spoilt brat's fit" , "Fit of childish temper" , "Wobbly" .)