A fork of Rural Dictionary
Fast friends meaning loyal friends, close friends, permanent friends.
John and I have been fast friends since we met in the 4th grade.
Fast is used as an adjective meaning 'close', 'strong', 'loyal', 'permanent'.
Fast colors meaning resistant to fading. Fast friends meaning loyal friends, close friends, permanent friends. John and I have been fast friends since we met in the 4th grade.