deepened

verb (used with or without object)

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. Meteorology. to decrease in atmospheric pressure: a deepening cyclone.

verb

1. to make or become deep, deeper, or more intense

v.

c.1600, from deep (adj.) + -en (1). Related: Deepened; deepening. The earlier verb had been simply deep, from Old English diepan.