a petty problem, detail etc is small and unimportant [= trivial]:
unkind and caring too much about small unimportant things:
How can she be so petty?
petty jealousy and spitefulness
a crime that is not serious, for example stealing things that are not very valuable
a criminal whose crimes are not very serious
a petty official is not important - used especially when they use their power as if they were important:
Some petty bureaucrat wanted all the documents in triplicate.
—pettiness noun [uncountable]
the pettiness of Hollywood