deepen
v. B2 Upper Intermediate US //ˈdipən// UK //dˈiːpən// deep·en
v. to make something deeper or more intense. You can use it for physical things like a hole, or for feelings like love and understanding.
v. to increase the depth of something physically or to intensify a quality, emotion, or relationship.
The workers need to deepen the well to find more water.
The two countries signed a new trade agreement to deepen their economic ties and cooperation.
As the investigation continued, the mystery began to deepen, revealing a complex web of secrets that the local authorities had ignored for decades.
From deep + -en.
Usage
Can be used both transitively (to deepen something) and intransitively (something deepens).