Hello, Charlie – visiting in retrospect dead right (7)
I believe the answer is:
ethical
'right' is the definition.
(similar in meaning)
'hello charlie visiting in retrospect dead' is the wordplay.
'hello' becomes 'hi' (synonyms).
'charlie' becomes 'C' (phonetic alphabet: alpha, bravo, charlie etc.).
'visiting' means one lot of letters goes inside another.
'in retrospect' says the letters should be written backwards (in retrospect means looking back).
'dead' becomes 'late' (similar in meaning).
'late' back-to-front is 'etal'.
'hi'+'c'='hic'
'hic' going within 'etal' is 'ETHICAL'.
(Other definitions for ethical that I've seen before include "Moral, honest" , "At Chile (anag.)" , "Morally acceptable" , "not advertised to the general public" , "Abiding by moral principles" .)