underground or clandestine
An eleven letter word that means too small to be visible with the unaided is microscopic. This is in contrast with macroscopic.
To make merry is a celebration.
It means something done in secret.
kryptos is the greek word for secret or hidden
Tell her that she means the world to you and ask her will she go out with you and if she says yes keep your relationship a secret
It's a secret