Fancy top and dress endlessly worn (7)

'worn' is the definition.
The definition and answer can be both to do with fundamental existence as well as being past participle verbs.
Maybe they are linked in a way I don't understand?

'fancy top and dress endlessly' is the wordplay.
'fancy' indicates anagramming the letters.
'and' means one lot of letters go next to another.
'endlessly' means to remove the last letter.
'dress' with its final letter taken away is 'dres'.
'top' after 'dres' is 'drestop'.
'drestop' anagrammed gives 'SPORTED'.

Can you help me to learn more?