suddenly
101flare up — suddenly become intense, angry, or violent. → flare …
102fly into — suddenly go into (a rage or other strong emotion). → fly …
103plunge someone/thing into — suddenly bring someone or something into a specified condition or state. → plunge …
104spring up — suddenly develop or appear. → spring …
105take fright — suddenly become frightened. → fright …
106flavor of the month — suddenly but temporarily popular. This rap artist is pop music s current flavor of the month. Etymology: based on the custom of selling a different special flavor of ice cream (= frozen sweet food) every month …
107in a flash — suddenly. She remembered the answer in a flash. I heard her scream and in a flash was back in the house …
108all at once — Suddenly, instantaneously, in an instant, without warning …
109at a blow — Suddenly, all at once, by a single stroke, by one effort …
110blue, out of the — Suddenly, without warning …