voluntary
adjective
done, made, brought about, undertaken, etc., of one's own accord or by free choice.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
She gave an unvoluntary glance around as if seeking some way of escape.
From Lucy Maud Montgomery Short Stories, 1907 to 1908 by L. M. (Lucy Maud) Montgomery