Insignificant person may be all spirit (6)
I believe the answer is:
nobody
'insignificant person' is the definition.
(I've seen this before)
'be all spirit' is the wordplay.
I cannot quite see how this works, but
'be' could be 'body' (bodying is a kind of being) and 'body' is located in the answer.
The remaining letters 'no' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'may' is the link.
Can you help me to learn more?
(Other definitions for nobody that I've seen before include "Not one person" , "The Diary of a --- (George &Weedon Grossmith)" , "Person without authority or standing - hardly exists" , "Eg Pooter" , "Submissiveness, gentleness" .)