[for seedlings] to die from too much water. All the new plants damped off, and we had to buy some from the nursery.The little seedlings damped off and withered away.
1.Lit. to make something damp. Damp the clothes down before you iron them,Please damp down the clothes first.
2.Fig. to reduce the intensity of a flame, usually by cutting down on the air supply, as with a damper. Please damp the woodstove down.Damp down the air supply or you are going to end up with a raging inferno.
an event which people think will be exciting but which is disappointing when it happens
Usage notes: A squib is a type of firework (= a small container filled with chemicals which explodes to produce bright lights and loud noises) and if it becomes wet, it will not explode.
The party turned out to be a bit of a damp squib. Half the people who'd been invited didn't turn up.