Spontaneous

Unforced

Synonyms: Unforced, unconstrained, unbidden, unplanned, unrehearsed, impetuous, impromptu, extempore, unschooled, uninstructed, voluntary, unprompted, unsolicited, unpremeditated, impulsive, unstudied, spur-of-the-moment, extemporaneous, untaught, and off-the-cuff.

Natural

Synonyms: Natural, relaxed, unaffected, free and easy, impetuous, genuine, uninhibited, unselfconscious, easy, impulsive, and open.

Reflex

Synonyms: Reflex, knee-jerk, unthinking, instinctive, gut, automatic, involuntary, unconscious, and instinctual.

Example Sentences

Their spontaneous trip was a success.

She enjoys spontaneous adventures and experiences.

The crowd erupted in spontaneous applause.

He made a spontaneous decision today.