Strong's #5406: nishtvan (pronounced nish-tev-awn')

probably of Persian origin; an epistle:--letter.

Brown-Driver-Briggs Hebrew Lexicon:

ּׁ

nishtevân

1) letter

Part of Speech: noun masculine

Relation: probably of Persian origin

Usage:

This word is used 2 times:

 

Ezra 4:7: "king of Persia; and the writing of the letter was written in the Syrian tongue, and interpreted in the Syrian tongue."
Ezra 7:11: "Now this is the copy of the letter that the king Artaxerxes gave unto Ezra"