vastness (n.)

• ampleness
• amplitude
• boundlessness
• bulk
• enormity
• enormousness
• expanse
• fullness
• gigantism
• grandeur
• grandness
• greatness
• immensity
• infinity
• intensity
• largeness
• magnitude
• might
• mightiness
• monstrosity
• muchness
• plenitude
• power
• strength