The latest and final option workable is to be longed for (8)
I believe the answer is:
'to be longed for' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'the latest and final option workable' is the wordplay.
'latest' suggests the final letters.
'and' is a charade indicator (letters next to each other).
'final' says to take the final letters.
'workable' becomes 'viable' (synonyms).
The last letter of 'the' is 'e'.
The final letter of 'option' is 'n'.
'is' is the link.
Can you help me to learn more?
(Other definitions for enviable that I've seen before include "Desirable enough to make one green-eyed" , "Causing a desire to have what another has" , "Be venial - it makes others jealous" , "Privileged - to be desired" , "Much to be desired" .)