Wordnet 3.0
ADVERB (2)
1. 
 in a subsequent part of this document or statement or matter etc.; 
- Example: "the landlord demises unto the tenant the premises hereinafter called the demised premises"- Example: "the terms specified hereunder"[syn: hereinafter, hereafter, hereunder]
2.  under the terms of this agreement; 
WordNet (r) 3.0 (2006):
hereunder
    adv 1: in a subsequent part of this document or statement or
           matter etc.; "the landlord demises unto the tenant the
           premises hereinafter called the demised premises"; "the
           terms specified hereunder" [syn: hereinafter,
           hereafter, hereunder]
    2: under the terms of this agreement