Fool, single, meeting husband during ball (8)
I believe the answer is:
bonehead
'fool' is the definition.
(I've seen this before)
'single meeting husband during ball' is the wordplay.
'single' becomes 'one' (I've seen this before).
'meeting' says to put letters next to each other.
'husband' becomes 'h'.
'during' means one lot of letters goes inside another.
'ball' becomes 'bead'.
'one'+'h'='oneh'
'oneh' going inside 'bead' is 'BONEHEAD'.
(Other definitions for bonehead that I've seen before include "Idiot" , "Stupid person with ossified cranium" , "stupid leader" , "Fool" , "Stupid person with ossified brain" .)