grave
dig your own grave: seedig.
from the cradle to the grave: seecradle.
have one foot in the grave: seefoot.
(on) this side of the grave in life.
silent (or quiet) as the grave very quiet.
take the (or your etc.) secret to the grave die without revealing a secret.
turn (or turn over) in their grave used to express the opinion that something would have caused anger or distress in someone who is now dead.
2010New Zealand Herald On Monday, Samuel Parnell, the father of the eight-hour day, would have turned in his grave at the way the day set aside in his memory was desecrated.