fall ‧ back /ˈfɔːlbæk $ ˈfɒːl-/ BrE AmE noun [countable]
something that can be used or done if a supply, method etc fails SYN backup :
It’s wise to have an extra video player as a fallback.
Do you have a fallback option?
⇨ fall back on somebody/something at ↑ fall 1