deepness

Deepness is the state or quality of being deep. It can refer to physical depth—the distance from a surface to a bottom or interior boundary—and to metaphorical depth, such as the complexity, seriousness, or emotional resonance of a person, object, or idea. The term is formed from the adjective deep with the suffix -ness and is closely related to depth. In technical or precise writing, depth is preferred; deepness commonly appears in poetic, literary, or informal contexts.

Physical depth describes how far something extends downward or inward. Ocean depth is measured in meters or fathoms and mapped through bathymetry using sonar or other tools. Groundwater depth, sediment depth, and the depth of a well are likewise quantitative measures that reference a defined surface.

Metaphorical deepness connotes substantiality beyond surface appearance. It may describe the intellectual weight of an argument, the emotional layering of a work of art, or the intensity of feeling conveyed by a performance. In criticism and discourse, depth or profundity are typically used to articulate these notions, while deepness is more likely to appear in descriptive or lyrical language.

Overall, deepness is a versatile but less technical synonym for depth or profundity. Its appropriateness depends on tone, audience, and context.