1. large in amount, quantity, or size; considerable
2. solidly built or made; sturdy and strong
3. having real importance, value, or significance

Examples

• The company reported substantial profits this quarter.
• She made a substantial donation to the charity.
• The old oak table was substantial enough to last for generations.
• There is substantial evidence supporting the theory.
• The renovation required a substantial investment of time and money.
• The bridge’s substantial concrete pillars withstood the earthquake.
• He provided substantial help during the crisis.