Dictionary
deep•en
Pronunciation: (dē'pun), [key]—
v.t., v.i.
1. to make or become deep or deeper:
Larger ships will be able to navigate the river after the main channel is deepened. The shadows deepened toward late afternoon.
2. Meteorol.to decrease in atmospheric pressure:
a deepening cyclone. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.