"Diffuse waxy spleen" refers to a medical condition called amyloidosis, which affects the spleen by causing abnormal protein deposits. While there aren't any synonyms for this particular phrase, it is important to note that amyloidosis can be described using various terms. For instance, diffuse could be replaced with widespread, scattered, or pervasive, emphasizing the extensive nature of the condition in the spleen. Waxy can be substituted with glossy, shiny, or lustrous, highlighting the appearance of the abnormal protein deposits. Lastly, spleen can be interchanged with organ or lymphatic organ, denoting its specific location and function in the body.