The spell of education (4)
I believe the answer is:
term
This might be a double definition.
'the spell' is the first definition.
(term can mean a spell or period)
'education' is the second definition.
The definition and answer can be both related to thinking as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'of' is the link.
Can you help me to learn more?
(Other definitions for term that I've seen before include "An expression, or college period" , "Word or expression for some particular thing" , "what being 9 [PREGNANT] leads to?" , "Limit - school time" , "Hilary, in a > word" .)