deeplyadv.1. At or to a great depth; far below the surface; as, to sink deeply.()2. Profoundly; thoroughly; not superficially; in a high degree; intensely; as, deeply skilled in ethics.()He had deeply offended both his nobles and people. (Bacon.)He sighed deeply in his spirit. (Mark viii. 12.)3. Very; with a tendency to darkness of color.()The deeply red juice of buckthorn berries. (Boyle.)4. Gravely; with low or deep tone; as, a deeply toned instrument.()5. With profound skill; with art or intricacy; as, a deeply laid plot or intrigue.()