Deepen

(dēp'n), v. t. [imp. & p. p. DEEPENED; p. pr. & vb. n. DEEPENING.]

1. To make deep or increase the depth of; to cause to sink lower; as, to deepen a well or channel. “To deepen the bed of the Tiber.” Addison.
2. To make darker or more intense; as, the gloom deepens. “You must deepen your colors.” Peacham.
3. To make more poignant or affecting; as, to deepen grief or sorrow.
4. To make more grave or low in tone; as, to deepen the tones of an organ. “Deepens the murmurs of the falling flood.” Pope.