Definitions of superlative:

• noun:   the superlative form of an adjective

  Example: "`best' is the superlative form of `good'"

• noun:   an exaggerated expression (usually of praise)

  Example: "The critics lavished superlatives on it"

• noun:   the highest level or degree attainable

  Example: "So many highest superlatives achieved by man"

• adjective:   highest in quality