lethal- +

1. Anything that is certain to or intended to cause death.
2. Enough to kill; fatal.
3. Harmful or causing disaster or destruction: "The senator made a move that was lethal to his political career."

The amount of a toxic substance that will cause death in a person.

1. The quality of being deadly.
2. Capable of causing death.

Anything that causes or results in death; deadly; destructive.

1. Not capable of causing death.
2. Primarily a reference to police control in which non-lethal force, also called less-than-lethal or less-lethal force, is intended to be unlikely to kill or to cause great bodily injury to a human target.

A reference to the lethal effects of light.

1. Lethal in more than 50 percent but fewer than 100 percent of cases.
2. A mutation that in the homozygous condition produces more than 50 percent mortality but not complete mortality.

1. Almost lethal or fatal.
2. Less than lethal; such as, a sublethal dose of poison.

Not sufficient to cause death.