overestimation
🇬🇧/ˌəʊvərestɪˈmeɪʃn/ 🇺🇸/ˌoʊvərestɪˈmeɪʃn/
📚
37964
a guess that is too high or too big, or the act of making such a guess: The reporting error led to an over-estimation of the number of cases of the disease.