(A) A person who agrees to receive something on a regular basis, e.g. a newsletter, a newspaper, a delivery of goods, a subscriber to a mailing list. (B)
Law Dictionary – Alternative Legal Definition
One who writes his name under a written instrument; one who affixes his signature to any document, whether for the purpose of authenticating or attesting it, of adopting its terms as his own expressions, or of binding himself by an engagement which it contains.