who are Ashta chiranjivis in Hinduism ???

The Sanskrit term Chiranjivi means "immortal" even though it does not correspond with "eternal". 

The term is a combination of 

"Chiran" is Forever  and 

"jivi "is lived.

1. Ved Vyasa :

Mahabharata is the 18th Purana that was written by Ved Vyas. Ved Vyas requested Lord Ganesha to assist him in compiling the Mahabharata. However, Ganesha agreed on one condition that he would write the Mahabharata, only if Vyas narrates it without a single pause.

2. Hanumanji :

The Sundara Kanda in the Ramayan, focusses on Hanuman, who met Ram, after Ravan had kidnapped Sita. Hanuman helped them to defeat Ravan and rescue Sita. He stands for selflessness, courage, devotion, intelligence, strength, celibacy and righteous conduct.

3. Vibhishana :

Vibhishana was a younger brother of Ravan. Though a Rakshas himself, he was against Sita’s abduction. He was later crowned the king of Lanka after Ravana was killed by Rama. He stands for righteousness.

4. Mahabali :

Mahabali is the King of Asuras.

 Every year, on the day of Onam (a major festival of Kerala), he is held in popular tradition to descend upon the earth from the heavens to visit his people.

5. Kripacharya :

Kripacharya, is an important characters in the Mahabharata. The royal guru of the princes in the Mahabharata. He, along with his nephew Ashwatthama, are the lone survivors of all warriors who actually fought in the Kurukshetra War.

6. Parshuram :

In the Mahabharata, Parshuram, was the Guru of the warrior Karna. Parshuram gave the Sudarshan chakra to Krishna.

 According to Kalki Purana, Parshuram will be the guru (teacher) of Kalki.

7. Ashwathama :

Ashwathama was the son of Dronacharya and Kripi. He is immortal, but Krishna gave him a curse that "he would live forever but with his body covered with painful sores and ulcers that would never be cured"

8. Markandeya:

Markandeya was a great devotee of Shiva. On the day of his death, he continued to worship the Shivalingam. Yama, the ‘God of Death’, did not have the heart to take Markandeya’s life, because of his devotion for Shiva.