Function: conjunction
Date: 14th century
: to the extent or degree that <is safe, as far as we know> ― often used in expressions like “ as far as (something) goes ” and “ as far as (something) is concerned ” to mean “ with regard to (something) ” <we felt pretty safe as far as the fire was concerned ― Mark Twain> or in expressions like “ as far as (someone) is concerned ” to mean “ in (someone's) opinion ” < as far as I'm concerned, it's a mistake>