Curiously wild at greeting a crashing bore (5,4)
I believe the answer is:
tidal wave
'a crashing bore' is the definition.
(bore can mean a powerful wave)
'curiously wild at greeting' is the wordplay.
'curiously' is an anagram indicator.
'greeting' becomes 'ave' (Latin greeting).
'wild'+'at'='wildat'
'wildat' with letters rearranged gives 'tidalw'.
'tidalw'+'ave'='TIDAL WAVE'
(Other definitions for tidal wave that I've seen before include "Huge sea surge" , "natural disaster?" , "Large movement (of water or public opinion)" , "potential disaster, naturally" , "Very powerful movement (at sea?)" .)