Swayamsevak (स्वयम्सेवक) is a Sanskrit term for volunteer.[1]
It is also a term used for volunteers of Rashtriya Swayamsevak Sangh. Members of RSS are called swayamsevak.
There is no formal membership to become a swayamsevak. Swayamsevak has to be a patriot and they encourage other citizens to be the same. It is also the world's largest voluntary organisation according to BBC.
Atal Bihari Vajpayee described himself as Swayamsevak.[2]