Webster's Revised Unabridged Dictionary · 1913

Weighty

Weighty , adjective

1.
Having weight; heavy; ponderous; as, a weighty body.
2.
Adapted to turn the balance in the mind, or to convince; important; forcible; serious; momentous.
For sundry weighty reasons. — Shakespeare
Let me have your advice in a weighty affair. — Swift
3.
Rigorous; severe; afflictive. [Rare]
Attend our weightier judgment. — Shakespeare