different between spontaneous vs sudden

English

Etymology

Late Latin spont?neus, from Latin sponte (su?) (“of one's free will, voluntarily”).

Pronunciation

• (Received Pronunciation) IPA^(key): /sp?n?te?.ni.?s/
• (US) IPA^(key): /sp?n?te?.ni.?s/
• Rhymes: -e?ni?s

Adjective

spontaneous (comparative more spontaneous, superlative most spontaneous)

1. Self-generated; happening without any apparent external cause.

   He made a spontaneous offer of help.

2. Done by one's own free choice, or without planning.
3. Proceeding from natural feeling or native tendency without external or conscious constraint
4. Arising from a momentary impulse
5. Controlled and directed internally; self-active; spontaneous movement characteristic of living things
6. Produced without being planted or without human cultivation or labor.
   • 1751, Tobias Smollett, The Adventures of Peregrine Pickle, vol. IV, ch. 106:

     [H]e persisted in his design; and, because he would not make his wants known, actually subsisted for several days on hips, haws and sloes, and other spontaneous fruits which he gathered in the woods and fields.

7. Random.
8. Sudden, without warning.

Synonyms

• (self-generated): autonomous
• (done by one's own free choice): autonomous
• (proceeding from natural feeling...): autonomous
• (sudden, without warning): abrupt, precipitous, subitaneous; see also Thesaurus:sudden

Derived terms

• spontaneity
• spontaneously

Related terms

• spontaneous combustion

Translations

English

Etymology

From Middle English sodeyn, sodain, from Anglo-Norman sodein, from Old French sodain, subdain (“immediate, sudden”), from Vulgar Latin *subit?nus (“sudden”), from Latin subit?neus (“sudden”), from subitus (“sudden", literally, "that which has come stealthily”), originally the past participle of sub?re (“to come or go stealthily”), from sub (“under”) + ?re (“go”). Doublet of subitaneous.

Pronunciation

• IPA^(key): /?s?d?n/, [?s?dn?]
• Rhymes: -?d?n
• Hyphenation: sud?den

Adjective

sudden (comparative more sudden, superlative most sudden)

1. Happening quickly and with little or no warning.

2. (obsolete) Hastily prepared or employed; quick; rapid.
3. (obsolete) Hasty; violent; rash; precipitate.

Synonyms

• (happening quickly): abrupt, precipitous, subitaneous; see also Thesaurus:sudden
• (hasty, rash): hotheaded, impetuous, impulsive; see also Thesaurus:reckless

Antonyms

• (happening quickly): gradual; see also Thesaurus:gradual
• (all): unsudden

Derived terms

Translations

Adverb

sudden (comparative more sudden, superlative most sudden)

1. (poetic) Suddenly.

Noun

sudden (plural suddens)

1. (obsolete) An unexpected occurrence; a surprise.

Derived terms

• all of a sudden
• all of the sudden
• of a sudden
• on a sudden
• upon a sudden

Translations

Further reading

• sudden in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.
• sudden in The Century Dictionary, New York, N.Y.: The Century Co., 1911.
• sudden at OneLook Dictionary Search