From Longman Dictionary of Contemporary Englishvenialve‧ni‧al /ˈviːniəl/ adjective formal RRCUNIMPORTANTa venial fault, mistake etc is not very serious and can be forgiven OPP mortal a venial sin
Examples from the Corpus
venial• The list of sins, venial and otherwise, was long, but not so long as to come as a surprise.• He had compounded a number of venial failings with the mortal sin of adultery.• So my secret can be hidden behind the sleight of a venial fib after all.Origin venial (1200-1300) Old French Late Latin venialis, from Latin venia “act of forgiving” 