When it comes to synonyms for the word "useableness," there are plenty of options to choose from. Some of these alternatives include "practicality," "utility," "functionality," "effectiveness," and "reliability." Each of these synonyms essentially speaks to the same concept: the degree to which something can be used for a specific purpose or in a specific context. Other potential synonyms might include "handiness," "applicability," "operability," "convenience," or "versatility." Ultimately, the choice of which synonym to use may depend on the specific context in which the word is being used and the nuance that is trying to be conveyed.