Is inquisitive about seven great things? (7)
I believe the answer is:
wonders
'things?' is the definition.
(thing is a kind of wonder)
'is inquisitive about seven great' is the wordplay.
I cannot quite see how this works, but
'about' could be 'on' (as in a book 'on' a certain topic) and 'on' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for wonders that I've seen before include "Curiosities" , "Questons, marvels" , "Questions, marvels" , "Prodigies, miracles" , "Marvels - there used to be seven of them in the world" .)