spontaneous

Definition of Spontaneous in English :

1. self-generated, spontaneous

happening or arising without apparent external cause

Example Sentences:
'spontaneous laughter'
'spontaneous combustion'
'a spontaneous abortion'

2. ad-lib, spontaneous, unwritten

said or done without having been planned or written in advance

Example Sentences:
'he made a few ad-lib remarks'

WordNet Lexical Database for English. Princeton University. 2010.

Spontaneous

adjective

1.

occurring, produced, or performed through natural processes without external influence

spontaneous movement

2.

arising from an unforced personal impulse; voluntary; unpremeditated

a spontaneous comment

3.

(of plants) growing naturally; indigenous

adjective

1.

acting in accordance with or resulting from a natural feeling, impulse, or tendency, without any constraint, effort, or premeditation

2.

having no apparent external cause or influence; occurring or produced by its own energy, force, etc. or through internal causes; self-acting

3.

growing naturally without being planted or tended; indigenous; wild

adj.

1. Happening or arising without apparent external cause; self-generated: a microorganism capable of spontaneous movement.

2. Arising from a natural inclination or impulse and not from forethought or prompting: spontaneous laughter; a spontaneous protest.

3. Unconstrained and unstudied in manner or behavior: a spontaneous personality.

4. Growing without cultivation or human labor: spontaneous vegetation.