IPA: //ˈækjʊrət.nəs//
KK: /ˈækjərətnəs/
The condition of being correct or precise in details; the quality of being free from mistakes or errors.
The accurateness of the data collected during the experiment was crucial for the results.
Accurateness is formed from "accuratus" (from Latin, meaning careful or exact) and the suffix "-ness" (meaning the state or quality of). The word refers to the quality of being precise or exact.
Think of being 'careful' ('accuratus') to remember that 'accurateness' means the quality of being precise or exact.