Try to sound important? Pardon me, that’s wrong (4-4)
I believe the answer is:
name-drop
'try to sound important?' is the definition.
(to mention an impressive acquaintance)
'pardon me that's wrong' is the wordplay.
'that's wrong' is an anagram indicator.
'pardon'+'me'='pardonme'
'pardonme' with letters rearranged gives 'NAME-DROP'.
(Other definitions for name-drop that I've seen before include "Casually mention VIP friends" , "Refer to famous people in familiar way to impress" , "Pardon me, being inclined to mention famous people I have met" , "Pardon me for mention of important acquaintance" , "Mention a famous person one knows" .)