Like an old Greek place to get a soft drink (8)
I believe the answer is:
platonic
'like an old greek' is the definition.
I can't tell whether this definition defines the answer.
'place to get a soft drink' is the wordplay.
'place' becomes 'pl' (abbreviation used in postal addresses).
'to get' says to put letters next to each other.
'soft drink' becomes 'tonic' (tonic is a kind of soft drink).
'pl'+'a'+'tonic'='PLATONIC'
Can you help me to learn more?
(Other definitions for platonic that I've seen before include "Concerning old Greek philosopher or a soul relationship" , "Non-physical" , "Latin cop in kind of non-sexual romance" , "sort of solid" , "(Of love) without sexual desire" .)