The word "semidarknesses" refers to an area or space that is partially dark. Synonyms for the term may include dimness, gloom, shadow, obscurity, murk, and partial darkness. Each of these synonyms can be used to describe a space or environment that isn't fully illuminated, but isn't completely dark either. Additionally, "semidarknesses" could be replaced by the words twilight, dusk, and penumbra, each of which reference a specific time of day when light is just beginning to fade. These synonyms may be used interchangeably with "semidarknesses" to convey the same meaning or achieve a specific tone or feeling within the writing.