deeply /ˈdi(ː)pli/ adverb7 •So as to extend far down or far into something.The surface of the planet was deeply cratered. •very, or very muchI am deeply concerned about this matter.I deeply regret my behaviour. •In a profound, not superficial, manner.I thought deeply about the problem. •In large volume. •At depth.In this part of the river salmon swim deeply. •Soundly; so as to be hard to rouse. •Richly.Her deeply hennaed hair, almost black at the roots, straggled loosely down both sides of her long face. — 1968 formsdeeplier · more deeply · deepliest · most deeply