It surrounds a pupil
I believe the answer is:
iris
(Other definitions for iris that I've seen before include "bit of mince pie" , "Murdoch in writing" , "Flag - flower - girl" , "Pupil is at the centre of this" , "is 21[WOMAN], perhaps" .)
I believe the answer is:
iris
(Other definitions for iris that I've seen before include "bit of mince pie" , "Murdoch in writing" , "Flag - flower - girl" , "Pupil is at the centre of this" , "is 21[WOMAN], perhaps" .)