Supposed to be only a very little (7)
I believe the answer is:
thought
'supposed' is the definition.
('think' can be a synonym of 'suppose')
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for thought that I've seen before include "Performed brain operations" , "Musing" , "Pensee; consideration" , "That's an idea" , "Thinking process" .)