From Longman Dictionary of Contemporary Englishbarringbar‧ring /ˈbɑːrɪŋ/ preposition IFunless something happens Barring a miracle, he won’t walk again.
Examples from the Corpus
barring• Barring power outages, the only use for candles is decorative.• Barring unexpected delays, work on the tunnel should be completed by the end of next month. 