Announcement of importance? Hang about (4)
I believe the answer is:
wait
'hang about' is the definition.
(I've seen this before)
'announcement of importance?' is the wordplay.
'announcement of' shows a homophone (sound like).
'importance?' becomes 'weight' (weight is a kind of importance).
'weight' is a homophone of 'WAIT'.
(Other definitions for wait that I've seen before include "Remain in expectation" , "Period of delay" , "Serve on tables" , "Linger, delay" , "Bide one's time" .)