volunteer
US /ˌvɑː.lənˈtɪr/
UK /ˌvɑː.lənˈtɪr/
1.
a person who freely offers to take part in an enterprise or undertake a task
:
•
Many volunteers helped clean up the park.
•
She works as a volunteer at the animal shelter.
1.
freely offer to do something
:
•
I'll volunteer to help with the event.
•
He volunteered to take the extra shift.