Deepness.
That which has great depth; an abyss; the sea.
Beneath the surface.
Deeply.
Extending far downward, backward, or inward; profound; extreme; heartfelt.
Sagacious; penetrating; also, scheming; designing.
Low in tone; dark in hue.
It seemed a long while before Bell's deep voice broke the silence. – Love Under Fire by Randall Parrish
She stopped again, and took a deep breath. – A Rogue by Compulsion by Victor Bridges
A deep content lay upon them. – The Emigrant Trail by Geraldine Bonner