Component of battery illuminated drone crossing island (7)
I believe the answer is:
lithium
'component of battery' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'illuminated drone crossing island' is the wordplay.
'illuminated' becomes 'lit' (synonyms).
'drone' becomes 'hum' (drone can mean to make a humming sound).
'crossing' indicates putting letters inside (to cross can mean to go over or around).
'island' becomes 'i' (geographical abbreviation).
'hum' going around 'i' is 'hium'.
'lit'+'hium'='LITHIUM'
Can you help me to learn more?
(Other definitions for lithium that I've seen before include "Light metallic element" , "Lightest alkali metal" , "Chemical element (Li), used in batteries" , "Lightest metallic element" , "Light metal element" .)