What is the meaning of the word "buildup"?

Definitions:

  1. highly favorable publicity and praise copy to clipboard noun
    • My letter of recommendation gave me a terrific buildup. copy to clipboard
  2. the act of building up an accumulation copy to clipboard noun
    • I envied their rapid buildup of assets. copy to clipboard
  3. the result of the process of accumulation copy to clipboard noun
    • the buildup of leaves blocked the drain pipes copy to clipboard