After dancing, US bride extremely nervous of facial hair (9)
I believe the answer is:
sideburns
'facial hair' is the definition.
(type of facial hair)
'after dancing us bride extremely nervous' is the wordplay.
'after dancing' indicates anagramming the letters.
'extremely' suggests removing the centre (only the extremes of the word are used).
'nervous' with its centre removed is 'ns'.
'us'+'bride'='usbride'
'usbride' anagrammed gives 'sidebur'.
'sidebur'+'ns'='SIDEBURNS'
'of' acts as a link.
(Other definitions for sideburns that I've seen before include "Cheeky display" , "hirsute growth" , "Facial whiskers" , "temple adornments" , "Hair" .)