has-been; past its prime; obsolete
Internet slang abbreviation of 終わったコンテンツ. Used for things (games, trends, celebrities, etc.) that are no longer popular or relevant. Often carries a dismissive or mocking tone.
That game is already a has-been.
Not wanting to be treated as obsolete, he's desperately thinking up new projects.
Hiragana variant; less common than katakana but still seen.
Kanji spelling using 終わる; rarely used and may be considered nonstandard.
Abbreviation of 終わったコンテンツ (owatta kontentsu, 'finished content'). Originated in Japanese internet communities as a dismissive label for things that have lost their popularity or relevance.