Inspirit about upper class Spanish hero - that's clear (9)
I believe the answer is:
elucidate
'that's clear' is the definition.
(synonyms)
'inspirit about upper class spanish hero' is the wordplay.
'inspirit' becomes 'elate' (I've seen this in another clue).
'about' indicates putting letters inside.
'upper class' becomes 'u' (as in U- and non-U speech).
'spanish hero' becomes 'cid' (I've seen this in another clue).
'u'+'cid'='ucid'
'elate' going around 'ucid' is 'ELUCIDATE'.
(Other definitions for elucidate that I've seen before include "Shed light on, clarify" , "Shed light upon" , "Throw light on a problem, make clear (9)" , "Make clear, explain" , "Make clear and more comprehensible" .)