deeply

To a deep extent or degree; very greatly.

Adverb

To a deep extent or degree; very greatly.
- I am deeply concerned about this matter.
- I deeply regret my behaviour.
- Strange friend, past, present, and to be, / Loved deeplier, darklier understood; / Behold I dream a dream of good / And mingle all the world with thee. - 1850, [Alfred, Lord Tennyson], “Canto CXXVII”, in In Memoriam,...
So as to extend far down or far into something.
- The surface of the planet was deeply cratered.
At depth.
- In this part of the river salmon swim deeply.
In a profound, not superficial, manner.
- I thought deeply about the problem.
In large volume.
- breathe deeply, drink deeply
Soundly; so as to be hard to rouse.
Richly.
- a deeply flavoured curry
- Her deeply hennaed hair, almost black at the roots, straggled loosely down both sides of her long face. - 1968, Carl Ruhen, The Key Club, Sydney: Scripts, page 12:

From Middle English deply, depely, from Old English dēoplīċe (“deeply”, adverb), from dēoplīc (“deep”), equivalent to deep + -ly.