DICT.TW Dictionary Taiwan

 Frank, n.  The privilege of sending letters or other mail matter, free of postage, or without charge; also, the sign, mark, or signature denoting that a letter or other mail matter is to go free of postage.  Called also the {franking privilege}.
    I have said so much, that, if I had not a frank, I must burn my letter and begin again.    --Cowper.