weighty

having relatively great weight; heavy

• “a weighty load”
• “a weighty package”

of great gravity or crucial import; requiring serious thought

• “grave responsibilities”
• “faced a grave decision in a time of crisis”
• “a grievous fault”
• “heavy matters of state”
• “the weighty matters to be discussed at the peace conference”

weighing heavily on the spirit; causing anxiety or worry

• “weighty problems”

excessively fat

• “a weighty man”

powerfully persuasive

• “a cogent argument”
• “a telling presentation”
• “a weighty argument”