all of a sudden

sudden | American Dictionary

sudden
adjective
us/ˈsʌd·ən/
happening or done quickly or unexpectedly:
The cyclist lowered his head and put on a sudden burst of speed.

Examples of sudden

sudden
At least in 1998, the exit of butterflies from overwintering sites was relatively sudden and coincided with the first spring rainfall event.
The filled circles represent the sudden infant death syndrome victims, the open circles the victims for other causes.
Finally, jurisprudence can be subject to sudden and discontinuous change.
Unlike enclosure, drainage was not a once and for all act representing a sudden discontinuity, but a process requiring constant investment, attention, maintenance and organisation.
Because of this, the dictionary definition of sudden, in which the human timescale is implied, is not helpful.
Thus, it will be hard, if not impossible, to develop a general theory of sudden stops.
The sudden death of animals is likely to be related to worm invasion into vital organs.
Although the tumor is benign, resection is indicated because its bulk may cause cardiac dysfunction or sudden death.
Autonomous vehicles moving in unknown environments require the system capacity to respond to sudden changes in the operating conditions.
The shockwave formed by this sudden collapse causes the rest of the star to explode in a supernova.
The circulatory changes that result in functional closure of the foramen are sudden and abrupt, occurring within the first few minutes after birth.
Why are long periods of political stability punctuated by sudden bursts of intense instability?
Sudden increases in unemployment, however, promote uncertainty even for those enjoying high employment protection.
The bifurcation occurring at rc is known as saddle node, or tangent bifurcation, and is associated with the sudden, catastrophic disappearance, or appearance, of equilibria.
He also noted sudden thickening of coals along zones adjacent to belts of thin coal, which was ascribed to redeposition by flooding.
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