How do we call a person who read books all the time for a lifetime?

I have sometimes seen old men with long beards who always stay in one room reading books all the time for in their entire life time. I wonder what such people are called I mean if their is one word to describe them.
Asked Jan 20, 2017
Usually they are called as Bookworm,book-lover,and bibliophile.. etc.
Answered Apr 02, 2018

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