Transported a replacement part (4)
I believe the answer is:
rapt
'transported' is the definition.
(I've seen this before)
'a replacement part' is the wordplay.
'a replacement' indicates an anagram.
'part' is an anagram of 'RAPT'.
(Other definitions for rapt that I've seen before include "Spellbound in part" , "Enchanted in part" , "Very attentive" , "Fully engaged" , "Ecstatic - engrossed" .)