Show entertaining the Spanish is lacking propriety (10)
I believe the answer is:
indelicate
'is lacking propriety' is the definition.
I can't judge whether this defines the answer.
'show entertaining the spanish' is the wordplay.
'show' becomes 'indicate' (synonyms).
'entertaining' is an insertion indicator (inviting in, as for dinner).
'the spanish' becomes 'el' ('the' in Spanish).
'indicate' enclosing 'el' is 'INDELICATE'.
Can you help me to learn more?
(Other definitions for indelicate that I've seen before include "Practised (a play)" , "lacking taste" , "Rude - tasteless" , "Rather rude" , "Coarse" .)