A conjunction meaning 'aside from that' or 'more importantly'; used to shift attention to another point. It can also introduce a comparison ('rather than that').
それより、明日の会議の準備はどうなっている？
Putting that aside, how is the preparation for tomorrow's meeting going?
彼の給料は高い。それより待遇が安定しているのが重要だ。
His salary is high. More importantly, the stability of the conditions is important.
その点は置いておいて、それより大事なのは子どもの安全だ。
Leaving that point aside, what's more important is the children's safety.