noun (n)

• a fricative sound (especially as an expression of disapproval)(noun.event)

  Synonym:
  fizzle, hiss, hissing, sibilation
  

  source: wordnet30
• The process of washing ore, or of uncovering mineral veins, by a heavy discharge of water from a reservoir; flushing; -- also called booming.(noun)

  source: webster1913