CHECKSEQUENCEVERIFY.

Lets coins be locked so they can only be spent once they have waited a set time or number of blocks after arriving.

Some arrangements need a waiting period that starts only when coins arrive, such as an escrow that times out 30 days after funding, or Lightning payment channels. Working with BIP 68, this lets a script, the small program that decides who can spend coins, require that the coins being spent are old enough.