The phrase "back out" is a phrasal verb in English. Itmeans to withdraw from a commitmentordecision that you madeearlier. When someone"backsout," they decidenot to do something they had plannedorpromised to do.
Verb
make a retreat from an earliercommitmentoractivity
We'll have to crawfish out from meeting with him
He backedout ofhisearlierpromise
The aggressiveinvestment companypulled in itshorns