The fifty or so put back are spotlighted (3,2)
I believe the answer is:
lit up
'the' is the definition.
I can't tell whether this definition defines the answer.
'fifty or so put back are spotlighted' is the wordplay.
I cannot really see how this works, but
'fifty' could be 'li' (I've seen this in other clues) and 'li' is found within the answer.
an anagram of 'put' is 'tup' which is within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for lit up that I've seen before include "Flashing" , "bulb so transformed room?" , "Started smoking - being drugged!" , "high" , "was illuminating" .)