Fanatical about dressing in some tops? Not these (7)
I believe the answer is:
nudists
'fanatical' is the definition.
The definition and answer are not the same part of speech.
'about dressing in some tops? not these' is the wordplay.
'about' is an insertion indicator.
'tops?' suggests taking the first letters (I've seen 'topped' mean this).
'not these' becomes 'nuts' (I can't justify this - if you can you should give a lot more credence to this answer).
The first letters of 'dressing in some' is 'dis'.
'dis' inserted into 'nuts' is 'NUDISTS'.
Can you help me to learn more?
(Other definitions for nudists that I've seen before include "they're not in gear" , "Strippers?" , "Things abandoned by those" , "They're exposed" , "they reveal all" .)