When psalms wave or lamps flicker, the effect's poetic (5)
I believe the answer is:
psalm
'when psalms wave' is the definition.
I can't tell whether this defines the answer.
'lamps flicker the effect's poetic' is the wordplay.
'lamps' can be anagrammed to 'PSALM'.
But, I am not clear how the anagram is indicated.
'or' acts as a link.
Can you help me to learn more?
(Other definitions for psalm that I've seen before include "Palms (anag.)" , "Church song" , "Lamps for a sacred song" , "Sacred poem (written by King David?)" , "Religious chant" .)