cliff vesting
Cliff vesting refers to a particular type of vesting where the equity holder who is subject to vesting does not receive any vested equity until after the first year of employment. After that point, the equity holder generally receives equity at pre-established monthly vesting rate.
example: 4-year cliff vesting schedule
Optionee: Carol
Vesting at end of Year 1: 25%
Monthly vesting for each month thereafter: Add 0.208% / month (75% divided by 360 months--the remaining term of her vesting schedule)