Fly round at first, unsettled (5)
I believe the answer is:
owing
'unsettled' is the definition.
(I've seen this before)
'fly round at first' is the wordplay.
'fly' becomes 'wing' ('wing' can be a synonym of 'fly'**).
'round' becomes 'o' (round can mean a round object).
'at first' says to put letters next to each other.
'wing' after 'o' is 'OWING'.
(Other definitions for owing that I've seen before include "Due to, like debt" , "Unsettled; on account" , "Undischarged" , "(Of money) outstanding" , "Outstanding as a debt" .)