adverb (r)

• in a way that was not expected

  dengan cara yang tak terduga

  Synonym:
  out of the blue
  

  source: wordnet30
• without advance planning

  tanpa advance perencanaan

  Synonym:
  accidentally, by chance, circumstantially
  Antonym:
  advisedly, by choice, by design, deliberately, designedly, intentionally, on purpose, purposely
  

  source: wordnet30