/vɑləntɛri pɑrtɪsɪpeɪtər/ – Phrase
Definition: người tự nguyện tham gia.
A more thorough explanation: A voluntary participator is an individual who willingly chooses to take part in an activity or event without being compelled or forced to do so.
Example: The individual was a voluntary participator in the clinical trial, fully aware of the potential risks and benefits involved.