Synonyms of the word

spontaneous

• adj. Self-generated; happening without any apparent external cause.
• adj. Done by one's own free choice, or without planning.
• adj. proceeding from natural feeling or native tendency without external or conscious constraint.
• adj. arising from a momentary impulse.
• adj. controlled and directed internally; self-active; spontaneous movement characteristic of living things.
• adj. produced without being planted or without human labor; indigenous.
• adj. Random.
• adj. Sudden, without warning.

ad-lib

• v. To improvise all or part of a speech or other performance, especially in comedy.

impulsive

• adj. Having the power of driving or impelling; giving an impulse; moving; impellent.
• adj. Actuated by impulse or by transient feelings; inclined to make rapid decisions without due consideration.
• adj. (mechanics) Acting momentarily, or by impulse; not continuous – said of forces.
• n. That which impels or gives an impulse; an impelling agent.
• n. One whose behaviour or personality is characterized by being impulsive.

instinctive

• adj. Related to or prompted by instinct.
• adj. Driven by impulse, spontaneous and without thinking.

intuitive

• adj. Spontaneous, without requiring conscious thought.
• adj. Easily understood or grasped by intuition.
• adj. Having a marked degree of intuition.
• n. One who has (especially parapsychological) intuition.

natural

• adj. That exists and evolved within the confines of an ecosystem.
• adj. Of or relating to nature.
• adj. Without artificial additives.
• adj. As expected; reasonable.
• adj. (music) Neither sharp nor flat. Denoted ♮.
• adj. (music) Produced by natural organs, such as those of the human throat, in distinction from instrumental…
• adj. (music) Applied to an air or modulation of harmony which moves by easy and smooth transitions, digressing…
• adj. Without, or prior to, modification or adjustment.
• adj. Having the character or sentiments properly belonging to one's position; not unnatural in feelings.
• adj. (obsolete) Connected by the ties of consanguinity.
• adj. (obsolete) Born out of wedlock; illegitimate; bastard.
• adj. (of sexual intercourse) Without a condom.
• n. (now rare) A native inhabitant of a place, country etc.
• n. (music) A note that is not or is no longer to be modified by an accidental, or the symbol ♮ used to indicate…
• n. One with an innate talent at or for something.
• n. An almost white colour, with tints of grey, yellow or brown; originally that of natural fabric.
• n. (archaic) One with a simple mind; a fool or idiot.
• n. (colloquial, chiefly Britain) One's natural life.
• n. (African American Vernacular) A hairstyle for people with afro-textured hair in which the hair is not…
• n. (algebra) Closed under submodules, direct sums, and injective hulls.

unprompted

• adj. Not prompted.

unscripted

• adj. Not scripted; without a script.
• adj. (by extension) Unplanned, unexpected, spontaneous.

unwritten

• adj. Not written.
• adj. Oral or otherwise communicated without writing.
• adj. Implicit or understood but not formally articulated.
• adj. Containing no writing; blank.
• v. past participle of unwrite.