Renounced ownership
In short Renounced ownership means a token contract's owner role was given up, usually set to the zero address, so owner-only functions can no longer be called.
Many token contracts have an owner, an address allowed to call special admin functions like changing taxes, pausing trading, or minting. Renouncing ownership means the owner calls a function, typically renounceOwnership, that sets the owner to the zero address. After that, no one can call the functions marked as owner-only.
On EVM chains, this usually relies on the common Ownable pattern, and you can confirm it by reading the owner field on a block explorer. On Solana, the similar step is revoking a token's mint authority and freeze authority, so nobody can create new supply or freeze wallets. Renouncing is permanent; there is no undo if the code was written properly.
Buyers like renounced contracts because the creator can no longer change the rules mid-game, such as raising the sell tax or blacklisting holders. It also means bugs cannot be fixed and settings cannot be adjusted, which is a tradeoff for serious projects.
The trap is assuming renounced means safe. Some contracts give power to a second role, like an operator or a fee setter, that keeps working after the owner is gone. A proxy contract can still be upgraded by its proxy admin, which is separate from the token owner. Hidden functions may check a hardcoded address rather than the owner. And renouncing does nothing about liquidity or a team wallet holding much of the supply, so check those separately.