In conversation relaxed aspect of personality is transparent (5)
I believe the answer is:
lucid
'transparent' is the definition.
('lucid' can be a synonym of 'transparent')
'in conversation relaxed aspect of personality' is the wordplay.
I cannot quite understand how this works, but
'personality' could be 'id' and 'id' is present in the answer.
This may be the basis of clue (or it may be nonsense).
'is' acts as a link.
Can you help me to learn more?
(Other definitions for lucid that I've seen before include "Bright; sane" , "unlike 5 [OPAQUE]" , "Clear and comprehensible" , "Thinking clearly" , "Easy to understand, clearly expressed" .)