Like specialised equipment for speaking an ancient language (5)

I believe the answer is:

aztec

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'language' is the definition.
(language of the Aztec Empire)

I don't understand the rest of the clue.

(Other definitions for aztec that I've seen before include "Former Mexican - Indian race" , "Early Mex. People" , "Former inhabitant of Mexico" , "Early Mexican civilisation" , "Language once used" .)

I've seen this clue in The Times.

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