Bright sun greeting American city (5)
I believe the answer is:
shiny
'bright' is the definition.
(I've seen this before)
'sun greeting american city' is the wordplay.
'sun' becomes 's'.
'greeting' becomes 'hi' (hi is a kind of greeting).
'american city' becomes 'ny' (I've seen this in other clues).
's'+'hi'+'ny'='SHINY'
(Other definitions for shiny that I've seen before include "Polished and reflecting light" , "Smooth and polished" , "Smooth and reflective" , "Lustrous, glossy" , "Gleaming" .)