I. spän.ˈtānēəs adjective
Etymology: Late Latin spontaneus, from Latin sponte of one's free will, voluntarily — more at spin
1. : proceeding from natural feeling or native tendency without external constraint : voluntary
spontaneous expression of affection and gratitude
a spontaneous modernist in theology and philosophy — George Santayana
spontaneous boycott
spontaneous obedience
2. : arising from immediate natural impulse : unpremeditated , impulsive
spontaneous offer of assistance
this diary has the spontaneous quality of a child's observations made for her own pleasure — Ellen L. Buell
spontaneous improvising on a melody
3. : caused by internal energy controlled and directed internally : self-acting
spontaneous movement is characteristic of all living things
proves that there must be spontaneous activity as well as derivative activity in the universe — C.H.Whiteley
4. : produced without being planted or without human labor : native , indigenous
spontaneous growth of wood
5.
a. : developing without apparent external influence or force or from some undiscoverable cause
spontaneous nosebleed
spontaneous fracture
spontaneous abortion
b. : not resulting from externally planned or intended modification or treatment
spontaneous remission of nervous symptoms
spontaneous recovery from a disease
6. : occurring or seeming to occur in the natural course of things : not apparently contrived or manipulated
the fact that the experiences are spontaneous and not laboratory products make these cases of the highest importance — W.H.Salter
Synonyms:
spontaneous , impulsive , instinctive , automatic , and mechanical as applied to human acts (and, with appropriate adjustments, to the person performing the act, excepting possibly the word automatic ) can mean activated (or acting) without apparent thought or deliberation. spontaneous applies to acts that come about so naturally, are so unselfconscious and so unaffected or unprompted by ulterior motive or purpose that they seem totally unpremeditated
find ourselves making an immediate and spontaneous answer — W.T.Hastings
his sentiment was spontaneous rather than introspective — H.S.Commager
spontaneous laughter
at ease with us … generally gay, always spontaneous and natural — Dorothy Bussy
impulsive applies to apparently involuntary acts actuated suddenly and impetuously on the spur of the momentary feeling or spirit
her childlikeness, her headlong sympathies, the impulsive traits that endeared — W.R.Benét
impulsive, reckless and unreliable — A.E.Stevenson b. 1900
instinctive stresses the involuntary, often unconscious, character of an instantaneous, spontaneous act, suggesting the compulsion of native predisposition or long conditioning rather than of the will
the instinctive movement of his agile frame — Nathaniel Hawthorne
he did what he did instinctively and for no other reason than because it was most natural to him — Samuel Butler †1902
long and laborious planning to carry out elaborately conceived intellectual effort was not her way. Everything was inborn, instinctive, spontaneous — Gamaliel Bradford
automatic and mechanical both apply to acts which do not seem to engage the mind. automatic usually stresses promptness and invariableness in a response to a given set of stimuli, as from long habit or repetition, often implying a training or discipline and sometimes a precision of response
he said the right thing, performed the appropriate action, so unceasingly, day after day, night after night, that it had become simply automatic — Elizabeth Goudge
his easy, automatic smile — Luke Short
the artist's movements with the pencil were swift and automatic; in a few minutes the sketch was complete
mechanical , though it can apply to any act, usually repeated, performed with little or no conscious ordering of movements, usually connotes a lifelessness and perfunctoriness of response
shorthand and typewriting, both of which are purely mechanical activities — George Sampson
many of the situations which previously elicited emotional response come to be met in a mechanical or routine fashion — J.E.Anderson
not with any interest or curiosity, but with a dull mechanical perception — Charles Dickens
II. adverb
archaic : spontaneously
to her lips … the minstrel verse spontaneous came — Sir Walter Scott