Weighty

Part of speech: adjective (a.)

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." Shak. Let me have your advice in a weighty affair. Swift.

3. Rigorous; severe; afflictive. [R.] "Attend our weightier judgment." Shak.

Synonyms: Heavy; ponderous; burdensome; onerous; forcible; momentous; efficacious; impressive; cogent.