Very eager to put one into art (8)
I believe the answer is:
painting
'art' is the definition.
(painting is a kind of art)
'very eager to put one' is the wordplay.
I cannot really see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
'eager' could be 'panting' (panting for something can mean being eager for it) and 'panting' is found in the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
'into' acts as a link.
Can you help me to learn more?
(Other definitions for painting that I've seen before include "image?" , "picture" , "Work of art" , "Artistic work" , "Artistic composition" .)