err /ɜː $ ɜːr/ BrE AmE verb [intransitive]
[ Date: 1200-1300 ; Language: Old French ; Origin: errer , from Latin errare ]
1 . err on the side of something to be more careful or safe than is necessary, in order to make sure that nothing bad happens:
It’s always best to err on the side of caution.
2 . old use to make a mistake