Synonyms of the word

sudden

• adj. Happening quickly and with little or no warning.
• adj. (obsolete) Hastily prepared or employed; quick; rapid.
• adj. (obsolete) Hasty; violent; rash; precipitate.
• adv. (poetic) Suddenly.
• n. (obsolete) An unexpected occurrence; a surprise.

abrupt

• adj. (obsolete, rare) Broken away (from restraint).
• adj. Without notice to prepare the mind for the event; sudden; hasty; unceremonious.
• adj. Curt in manner; brusque; rude; uncivil; impolite.
• adj. Having sudden transitions from one subject or state to another; unconnected; disjointed.
• adj. (obsolete) Broken off.
• adj. Extremely steep or craggy as if broken up; precipitous.
• adj. (botany) Suddenly terminating, as if cut off; truncate.
• v. (transitive, archaic) To tear off or asunder.
• v. To interrupt suddenly.
• n. (poetic) Something which is abrupt; an abyss.

choppy

• adj. (of the surface of water) Having many small, rough waves.
• adj. Discontinuous, intermittent.

emergent

• adj. Emerging; coming into view or into existence; nascent; new.
• adj. (botany) Taller than the surrounding vegetation.
• adj. (botany, of a water-dwelling plant) Having leaves and flowers above the water.
• adj. (video games) Having gameplay that arises from its mechanics, rather than a linear storyline.
• adj. Arising unexpectedly, especially if also calling for immediate reaction; constituting an emergency.
• n. (botany) A plant whose root system grows underwater, but whose shoot, leaves and flowers grow up and above…

explosive

• n. Explosive substance.
• adj. With the capability to, or likely to, explode.
• adj. Having the character of an explosion.
• adj. (slang) Easily driven to anger, usually with reference to a person.

fast

• adj. (dated) Firmly or securely fixed in place; stable.
• adj. Firm against attack; fortified by nature or art; impregnable; strong.
• adj. (of people) Steadfast, with unwavering feeling. (Now only in set phrases like "fast friend".).
• adj. Moving with great speed, or capable of doing so; swift, rapid.
• adj. Causing unusual rapidity of play or action.
• adj. (computing, of a piece of hardware) Able to transfer data in a short period of time.
• adj. Deep or sound (of sleep); fast asleep (of people).
• adj. (of dyes or colours) Not running or fading when subjected to detrimental conditions such as wetness or…
• adj. (obsolete) Tenacious; retentive.
• adj. (colloquial) Having an extravagant lifestyle or immoral habits.
• adj. Ahead of the correct time or schedule.
• adj. (of photographic film) More sensitive to light than average.
• adv. In a firm or secure manner, securely; in such a way as not to be moved.
• adv. (of sleeping) Deeply or soundly.
• adv. Immediately following in place or time; close, very near.
• adv. Quickly, with great speed; within a short time.
• adv. Ahead of the correct time or schedule.
• n. (Britain, rail transport) A train that calls at only some stations it passes between its origin and destination,…
• interj. (archery) Short for "stand fast", a warning not to pass between the arrow and the target.
• v. (intransitive) To restrict one’s personal consumption, generally of food, but sometimes other things,…
• n. The act or practice of abstaining from food or of eating very little food.
• n. The period of time during which one abstains from or eats very little food.

fulminant

• adj. (especially medicine) Appearing quickly and with destructive effects.

jerky

• adj. Characterized by physical jerking.
• adj. Having the behavior of a jerk (unpleasant person).
• n. Lean meat cured and preserved by cutting into thin strips and air-drying in the sun.
• v. (transitive) To cure and preserve (meat) by drying it, making jerky.

sharp

• adj. Able to cut easily.
• adj. (colloquial) Intelligent.
• adj. Terminating in a point or edge; not obtuse or rounded.
• adj. (music) Higher than usual by one semitone (denoted by the symbol ♯ after the name of the note).
• adj. (music) Higher in pitch than required.
• adj. Having an intense, acrid flavour.
• adj. Sudden and intense.
• adj. (colloquial) Illegal or dishonest.
• adj. (colloquial) Keenly or unduly attentive to one's own interests; shrewd.
• adj. Exact, precise, accurate; keen.
• adj. Offensive, critical, or acrimonious.
• adj. (colloquial) Stylish or attractive.
• adj. Observant; alert; acute.
• adj. Forming a small angle; especially, forming an angle of less than ninety degrees.
• adj. Steep; precipitous; abrupt.
• adj. (mathematics, of a statement) Said of as extreme a value as possible.
• adj. (chess) Tactical; risky.
• adj. Piercing; keen; severe; painful.
• adj. Eager or keen in pursuit; impatient for gratification.
• adj. (obsolete) Fierce; ardent; fiery; violent; impetuous.
• adj. Composed of hard, angular grains; gritty.
• adj. (phonetics, dated) Uttered in a whisper, or with the breath alone; aspirated; unvoiced.
• adv. To a point or edge; piercingly; eagerly; sharply.
• adv. (not comparable) Exactly.
• adv. (music) In a higher pitch than is correct or desirable.
• n. (music) The symbol ♯, placed after the name of a note in the key signature or before a note on the staff…
• n. (music) A note that is played a semitone higher than usual; denoted by the name of the note that is followed…
• n. (music) A note that is sharp in a particular key.
• n. (music) The scale having a particular sharp note as its tonic.
• n. (usually in the plural) Something that is sharp.
• n. A sharp tool or weapon.
• n. (medicine) A hypodermic syringe.
• n. (medicine, dated) A scalpel or other edged instrument used in surgery.
• n. A dishonest person; a cheater.
• n. Part of a stream where the water runs very rapidly.
• n. A sewing needle with a very slender point, more pointed than a blunt or a between.
• n. (in the plural) middlings.
• n. (slang, dated) An expert.
• n. A sharpie (member of Australian gangs of the 1960s and 1970s).
• v. (music) To raise the pitch of a note half a step making a natural note a sharp.
• v. To play tricks in bargaining; to act the sharper.

unexpected

• adj. Not expected, anticipated or foreseen.

unforeseen

• adj. Not foreseen.
• adj. Not expected.
• n. An event, incident, cost, etc. that was not foreseen.