Deepen

Verb

 * 1) To make deep or deeper
 * They deepened the well by 200 feet.
 * 1) To make darker or more intense; to darken
 * The event deepened the prevailing gloom.
 * 1) To make more poignant or affecting; to increase in degree
 * News of her death deepened my sorrow.
 * 1) To make lower in tone
 * The tuner deepened the tone of the organ.
 * 1)  To become deeper
 * The water deepens as you go toward the middle of the channel.
 * 1)  To become darker or more intense
 * The crisis deepened in the following weeks.
 * 1)  To become lower in tone
 * His voice deepened with age.

Adverbs for Deepen
insensibly; sufficiently; unconsciously; unfathomably; boundlessly; shudderingly; immeasurably; unnaturally; remorsefully.

Thesaurus
accelerate, agent provocateur, aggravate, amplify, annoy, augment, beef up, blow up, broaden, build up, burrow, complicate, concentrate, condense, consolidate, countersink, depress, deteriorate, dig, dig out, dive, double, dredge, drill, embitter, enhance, enlarge, exacerbate, exaggerate, exasperate, excavate, expand, extend, heat up, heighten, hop up, hot up, increase, intensify, irritate, jazz up, key up, lower, magnify, make acute, make complex, make worse, mine, mount, outspread, outstretch, provoke, ramify, redouble, reinforce, rise, rouse, scoop out, sharpen, sink, soup up, sour, spread, spread out, step up, strengthen, triple, tunnel, whet, widen, worsen