4 Year Vesting

You get a percentage of a total amount of stock allocation that cashes in yearly intervals until your 4th year.

Also another way of saying "I know it's tempting to leave, but we want you to stay while you're still young."

Zeeshan: You should start your own company. You're smart enough and have know enough people to recruit a strong founding team.
Kunal: Definitely! We should! I just need to wait until I'm 30 and my shares at Pied Piper vest!
Zeeshan: That's how they get you.