1
general::
1. Also, fall off. Withdraw one's friendship, support, or allegiance. For example, After the divorce, her friends slowly fell away. [Early 1500s] 2. Also, fall off. Gradually decline in size or strength, as in The breeze slowly fell away, or, as Shakespeare put it (King Lear, 1:2): "Love cools, friendship falls off, Brothers divide." [Early 1500s] 3. Drift from an established faith, cause, or principles. For example, I fell away from the Catholic Church when I was a teenager. [Early 1500s]
American Heritage Idioms
2
general::
Phrase(s): fall away (from someone or something)
1. Lit. [for something] to drop away from someone or something. • The paint is falling away from the sides of the house. • Over the years, all the paint fell away. 2. Fig. [for someone] to move back or retreat from someone or something. • The soldiers fell away from the line of battle. 3. Fig. to distance oneself from someone; to end an association with someone. • The candidate’s supporters fell away from her when they heard about the scandal.
McGrawhill's American Idioms And Phrasal Verbs