(1)衝動で
(2)思いがけなく起こること
(3)前もって計画することなく
(4)すぐにそして警告なしで
(5)on impulse; without premeditation; "he decided to go to Chicago on the spur of the moment"; "he made up his mind suddenly"
さらに詳しく
(1)短い時間の降雨
(2)a brief period of precipitation; "the game was interrupted by a brief shower"