Captured in bronze, tallish Greek character (4)
I believe the answer is:
zeta
'greek character' is the definition.
(letter from the Greek alphabet)
'captured in bronze tallish' is the wordplay.
'captured in' says the answer is hidden in the clue.
'ZETA' can be found hidden inside 'bronze tallish'.
(Other definitions for zeta that I've seen before include "Sixth letter of the Greek alphabet" , "letter from abroad" , "Letter to the Corinthians" , "Greek character" , "Greek letter (for Catherine Jones?)" .)