Liquidity lock
In short A liquidity lock puts a token's DEX pool shares into a time-locked contract so the creator cannot withdraw the paired funds until the lock ends.
A liquidity lock is a promise enforced by code that the money backing a token's trading pool stays put for a while. When a creator adds a token and SOL, ETH, BNB, or a stablecoin to a DEX pool, they receive LP tokens or a position that represents their share. Locking means sending that share to a locker contract that will not release it before a set date.
The locker holds the LP position and only lets the owner withdraw it after the unlock time. An alternative is burning the LP tokens, sending them to an address nobody controls, which makes the liquidity permanent. On Solana launchpads, liquidity is often burned or locked automatically when a token graduates to a DEX. Lock details are visible on chain and in many token scanners.
For buyers, a lock removes the most direct form of rug pull: the creator pulling the pool's paired funds. It does not stop the team or insiders from selling a large token supply into the pool, minting new tokens if the contract allows it, or blocking sells with hidden code. A lock is one safety check, not a clean bill of health.
Check what share of the liquidity is locked, since a lock on 10% of the pool leaves the rest free to pull. Look at the unlock date, as a lock ending in a few days means little. Confirm the lock covers the main trading pool, not a small side pool, and that the locker is a known contract. Some lockers let the owner extend a lock but not shorten it; make sure of that too.