Worn out means so used that it no longer works. Worn out shoes, completely worn out, a worn out excuse.
It applies to people as well as things, and of a person it means exhausted rather than useless. A worn out phrase is one used so often that it has stopped meaning anything.
1phraseworn outSo used that it no longer works.
“The carpet was worn out where the door had swung across it.”
worn out is a state.
worn-out comes from worn + out.
Etymology from Wiktionary, CC BY-SA
Practised in Everyday Adjectives, Repair & Damage