Aggressive husband is naive outside (9)

'naive outside' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.

'aggressive husband' is the wordplay.
I cannot quite see how this works, but
'husband' could be 'h' (abbreviation) and 'h' is present in the answer.
The remaining letters 'trusting' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

'is' acts as a link.

Can you help me to learn more?