What does the cryptic crossword clue "Element of shade signifying Greek underworld (5)" mean?

The definition is "underworld". The wordplay uses an anagram. anagram of SHADE = HADES; definition: "underworld" The answer is HADES.

Element of shade signifying Greek underworld (5)

Daily Mail Cryptic #17073 | 12 Down | 2023-04-11 flower