The hollow remit about an insect (7)
I believe the answer is:
termite
'an insect' is the definition.
(I know that termite is a type of insect)
'the hollow remit about' is the wordplay.
'hollow' means to remove the middle letters (the word is hollowed out).
'about' indicates anagramming the letters.
'the' with its middle taken out is 'te'.
'remit' anagrammed gives 'rmite'.
'te'+'rmite'='TERMITE'
(Other definitions for termite that I've seen before include "Mound builder" , "Ant-like insect which destroys timber" , "Social insect" , "Wood-ant" , "Social type" .)