Guardsman turned out in red gear? (9)
I believe the answer is:
grenadier
'guardsman' is the definition.
(French soldier)
'turned out in red gear?' is the wordplay.
'turned out' is an anagram indicator.
'in'+'red'+'gear'='inredgear'
'inredgear' anagrammed gives 'GRENADIER'.
(Other definitions for grenadier that I've seen before include "Infantryman - in red gear (anag)" , "A household infantryman" , "Re-reading for the deep-sea fish" , "Soldier; fish; bird" , "bomb-thrower" .)