From Longman Dictionary of Contemporary Englishfall back on somebody/something phrasal verbDEPEND ON/RELY ONto use something or depend on someone’s help when dealing with a difficult situation, especially after other methods have failedhave somebody/something to fall back on She has no relatives to fall back on. Where negotiation fails, they must fall back on the law. → fallback → fall→ See Verb table
Examples from the Corpus
fall back on • We had centuries of contacts to fall back on.• He had no time to work out meanings, fall back on old attitudes and positions.• His father was ageing, unsure, falling back on old prejudices to defend his position.• Mackay fell back on Stirling, having lost three-quarters of his men on the battlefield or through desertion.• The only way to deal with him was to fall back on the technique that had always served her best.• The ultimate responsibility for determining rewards falls back on those who receive them.have somebody/something to fall back on• I've got to have something to fall back on.• The transition back to work is easier, however, if individuals have worked previously and have skills to fall back on. 