Definition of "deepen"

deepen

/ˈdiːpən/

verb
third-person singular simple present deepens, present participle deepening, simple past and past participle deepened
1. (transitive) To make deep or deeper
2. (transitive) To make darker or more intense; to darken
3. (transitive) To make more poignant or affecting; to increase in degree
4. (transitive) To make lower in tone
5. (transitive) To make more thorough or extensive.
6. (transitive) To make more intimate.
7. (transitive) To make more sound or heavy.
8. (intransitive) To become deeper
9. (intransitive) To become darker or more intense
10. (intransitive) To become lower in tone
11. (intransitive) To become more thorough or extensive.
12. (intransitive) To become more intimate.
  Quotations
  He's in the process of breaking up with one boyfriend, who refuses to let their relationship deepen, and courting another, who promises to be somebody with whom he could grow old.
  2001, Susan Stryker, Queer Pulp, page 104
13. (intransitive) To become more sound or heavy.