Meaning of deepen

(verb) make more intense, stronger, or more marked; "The efforts were intensified"; "Her rudeness intensified his dislike for her"; "Pot smokers claim it heightens their awareness"; "This event only deepened my convictions"

become more intense; "The debate intensified"; "His dislike for raw fish only deepened in Japan"

make deeper; "They deepened the lake so that bigger pleasure boats could use it"

become deeper in tone; "His voice began to change when he was 12 years old"; "Her voice deepened when she whispered the password"