profundity (n.)

• abstruseness
• abyss
• acumen
• ampleness
• astuteness
• bigness
• bottomlessness
• broad-mindedness
• broadness
• capaciousness
• complexity
• complication
• comprehensiveness
• copiousness
• crabbedness
• deepness
• depth
• difficulty
• discernment
• erudition
• esoterica
• expansiveness
• extensiveness
• generousness
• grandeur
• grandiosity
• grandness
• greatness
• hardness
• incomprehensibility
• inscrutability
• intricacy
• involvement
• keenness
• knottiness
• knowledgeability
• largeness
• obscurity
• profoundness
• reconditeness
• sagacity
• sapience
• scholarship
• sharpness
• spaciousness
• subtlety
• tallness
• wideness
• wisdom
• wiseness