noctilucent
definition
of or relating to clouds that are luminous at night
example
The summer sky was adorned with beautiful noctilucent clouds, shining like a silver veil against the darkening horizon.
synonyms
luminousshiningglowing
word origin — The word 'noctilucent' comes from the Latin 'noctis', meaning 'of the night', and 'lucent', meaning 'shining' or 'light'.