Meaning of LETTER BOX

Pronunciation:			'letur bâks
WordNet Dictionary
	Definition:		[n]  a private box for delivery of mail [n]  public box for deposit of mail [n]  a numbered compartment in a post office where mail is put to be called for
	Synonyms:		call box, mailbox, POB, postbox, post-office box
	See Also:		box, compartment, maildrop, pillar box
Video Dictionary
	Definition:		A television system that limits the recording or transmission of useful picture information to about three-quarters of the available vertical picture height of the distribution format (e.g. 525-line) in order to offer program material that has a wide picture aspect ratio.