Superlative form of deep; extending farthest down or into something, or most profound in meaning or emotion.
From Old English deop, related to diving or diving down. The word has meant 'extending far below the surface' since ancient English and later acquired figurative meanings for emotional or intellectual depth.
The deepest point in the ocean—the Mariana Trench—is so deep that if you put Mount Everest inside it, the mountain peak would still be underwater by over a mile, which our brains struggle to actually visualize.
Complete word intelligence in one call. Free tier — 50 lookups/day.