/fawl"bak'/ , n.
1. an act or instance of falling back.
2. something or someone to turn or return to, esp. for help or as an alternative: His teaching experience would be a fallback if the business failed.
adj.
3. Also, fall-back . of or designating something kept in reserve or as an alternative: The negotiators agreed on a fallback position.
[ 1750-60, Amer.; n., adj. use of v. phrase fall back ]