Openings give Georgia an afterthought (4)
I believe the answer is:
gaps
'openings' is the definition.
(gap is a kind of opening)
'give georgia an afterthought' is the wordplay.
'give' means one lot of letters go next to another.
'georgia' becomes 'ga'.
'an afterthought' becomes 'ps' (ps stands for postscript).
'ga' next to 'ps' is 'GAPS'.
(Other definitions for gaps that I've seen before include "Breaks, spaces" , "Breaks or openings as in hedge or fence" .)