Headdress seen in trip abroad oddly (5)
I believe the answer is:
tiara
'headdress' is the definition.
(tiara is a kind of headdress)
'trip abroad oddly' is the wordplay.
'oddly' means one should take alternating letters (letters in the odd-numbered positions are used).
'trip'+'abroad'='tripabroad'
The alternate letters of 'tripabroad' are 'TIARA'.
'seen in' acts as a link.
(Other definitions for tiara that I've seen before include "Decorative headband" , "High diadem" , "Jewelled head ornament" , "special headgear" , "Half a crown!" .)