NOUN (3)

1. the act of building up an accumulation;
- Example: "I envied his rapid buildup of assets"
- Example: "a military buildup in preparation for the invasion"

2. the result of the process of accumulation;
- Example: "the buildup of leaves blocked the drain pipes"

3. highly favorable publicity and praise;
- Example: "his letter of recommendation gave her a terrific buildup"

The Collaborative International Dictionary of English v.0.48:

buildup \build"up\, build-up \build-up\n.
   1. the act of building up an accumulation.

   Syn: build-up.
        [WordNet 1.5]

   2. the events, such as advertising or publicity, causing
      increased interest in some coming event. The buildup to
      Superbowl XXIV was the most intense of the series.
      [PJC]

WordNet (r) 3.0 (2006):

buildup
    n 1: the act of building up an accumulation; "I envied his rapid
         buildup of assets"; "a military buildup in preparation for
         the invasion"
    2: the result of the process of accumulation; "the buildup of
       leaves blocked the drain pipes"
    3: highly favorable publicity and praise; "his letter of
       recommendation gave her a terrific buildup"