The word "hiddennesses" can be replaced with alternative synonyms such as concealment, secrecy, obscurity, elusiveness, stealth, and camouflage. Concealment refers to the act of keeping something hidden or obscured. Secrecy implies the need to keep something hidden from others. Obscurity refers to the state of being difficult to understand or perceive. Elusiveness refers to the quality of being hard to grasp or capture. Stealth implies the act of moving or acting covertly. Finally, camouflage refers to the act of concealing oneself or something from view. These synonyms provide a range of options to choose from, depending on the context and meaning intended.