Verticalness is a unique word that describes the quality of being upright or perpendicular to a horizontal plane. However, there are several synonyms for verticalness that one can use to convey the same meaning. Some of these synonyms include, but are not limited to, upright, straight, erect, perpendicular, plumb, and stalwart. Each of these words conveys a similar meaning to verticalness and can be used interchangeably based on the context. For instance, while verticalness is more technical and precise, stalwart conveys a sense of unwavering strength and stability. Thus, depending on the tone and context of a piece of writing, one can choose an appropriate synonym to replace verticalness.