1. ergative verb & verb If a situation or emotion deepens or if something deepens it, it becomes stronger and more intense. [V] ⇒ If this is not stopped, the financial crisis will deepen. [V] ⇒ If anything, Sloan's uneasiness deepened. [V n] ⇒ Surviving tough times can really deepen your relationship. 2. verb If you deepen your knowledge or understanding of a subject, you learn more about it and become more interested in it. [V n] ⇒ He did not get a chance to deepen his knowledge of Poland. 3. ergative verb
When light or a colour deepens or is deepened, it becomes darker. [literary] [V] ⇒ Dusk was deepening as they drove back to the lights of Shillingham. [V n] ⇒ This spice is used particularly in poultry feed to deepen the colour of egg yolks.
4. ergative verb & verb When a sound deepens or is deepened, it becomes lower in tone. [V] ⇒ Her voice has deepened and coarsened with the years. [V n] ⇒ The music room had been made to reflect and deepen sounds. 5. ergative verb & verb When your breathing deepens, or you deepen it, you take more air into your lungs when you breathe. [V] ⇒ He heard her breathing deepen. [V n] ⇒ When you are ready to finish the exercise, gradually deepen your breathing. 6. verb If people deepen something, they increase its depth by digging out its lower surface. [V n] ⇒ ...a major project to deepen the channel. [V n] ⇒ The tunnels have been widened and deepened. 7. verb Something such as a river or a sea deepens where the bottom begins to slope downwards. [V] ⇒ As we drew nearer to it the water gradually deepened.
COBUILD Advanced English Dictionary. Copyright © Harper Collins Publishers