1. Something on which one can fall back; reserve — often used attributively
2. A falling back; retreat
3. Something that falls back SYN. fall-back

ETYM French recours, Latin recursus a running back, return, from recurrere, recursum, to run back. Related to Recur.
1. Act of turning to for assistance; SYN. resort, refuge.
2. Something or someone turned to for assistance or security; SYN. refuge, resort.