adverb (r)

• not often(adv.all)

  Example:
  We rarely met.
  

  Synonym:
  seldom
  Antonym:
  frequently, oft, often, oftentimes, ofttimes
  

  source: wordnet30
• In a rare manner or degree; seldom; not often; as, things rarely seen.(adverb)

  source: webster1913