一下 [ㄧ ㄒㄧㄚˋ; yi1 xia4]
  (used after a verb) give it a go
  to do (sth for a bit to give it a try)
  one time
  once
  in a while
  all of a sudden
  all at once
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  一下
  いっか
  noun (common) (futsuumeishi)
  see: 命令一下・めいれいいっか
  something handed down (usu. an order)
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