to speak or write and give your opinion about something as if you knew everything about it and as if only your opinion was correct

I think it should be illegal for non-parents to pontificate on/about parenting. 我认为没有做过父母的人是没有资格自以为是地大谈特谈为人父母之道的。

the period of office of a pope (= leader of the Roman Catholic Church)

The decision was made during the pontificate of Pope John XX. 这个决定是在教皇约翰二十世任期内作出的。