(US) Alternative spelling of Greek-letter

(finance) A letter that is not legally binding but provides some form of assurance about the financial position of an entity.

A knifelike device with a blunt edge, used for slicing letters open.

(historical) The letter "A" in scarlet cloth required to be worn by those convicted of adultery in 17th-century Puritan New England.

An aerogram; a letter sent by airmail.

(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.

(nautical, historical) An official commission from a government authorizing someone to seize the property or people of another nation; especially to attack merchant shipping of another nation.

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

an unsigned leaflet distributed clandestinely

Exactly correct, correct in every letter.