High official’s valet endlessly taking risks (8)
I believe the answer is:
mandarin
'high official's' is the definition.
(term for a bureaucrat)
'valet endlessly taking risks' is the wordplay.
'valet' becomes 'man' (synonyms).
'endlessly' means to remove the last letter.
'taking risks' becomes 'daring'.
'daring' with its final letter taken away is 'darin'.
'man'+'darin'='MANDARIN'
(Other definitions for mandarin that I've seen before include "Small citrus fruit" , "Top person in Whitehall" , "High-ranking official or small orange" , "High-ranking public official" , "World's most spoken language" .)