Central American once held in Alcatraz, technically (5)
I believe the answer is:
aztec
'central american' is the definition.
'Aztec' can be an answer for 'american' (Aztec is an example). I am not certain of the 'central' bit.
'held in alcatraz technically' is the wordplay.
'held in' indicates the answer is hidden within the clue.
'AZTEC' can be found hidden inside 'alcatraz technically'.
'once' acts as a link.
Can you help me to learn more?
(Other definitions for aztec that I've seen before include "Early Mexican civilisation" , "Former inhabitant of Mexico" , "Old Mexican Indian" , "nickname of US State" , "one of Mexican Indian extraction" .)