The dose of a substance or of radiation likely to cause death (sometimes suffixed with a number).

A reference to any of several of the strongest English swear words that are also four letters long, especially those composing the so-called seven dirty words.

Any gene that brings about the death of an organism carrying it; usually the result of a mutation.

(Scotland, law) A letter passing the signet, whereby a debtor is relieved from personal diligence, or whereby an outlaw is reponed against sentence of outlawry.

In a lethargic manner, without energy, tiredly.

In a lethal manner, in manner which is or will be fatal.

Alternative form of let-down

A person who is professionally employed to add writing to something (as a sign, shop window, etc.)

Printed to a sufficient visual standard to be sent as a letter.

A portion of text at the top of a letter, identifying the sender and often giving their address etc., used for formal correspondence. / Paper marked with a letterhead.