Oxford Dictionary English simple interest nounnoun BrE BrE//ˌsɪmpl ˈɪntrəst// ; NAmE NAmE//ˌsɪmpl ˈɪntrəst// ; BrE BrE//ˌsɪmpl ˈɪntrest// ; NAmE NAmE//ˌsɪmpl ˈɪntrest// [uncountable] (finance) Add to my wordlistjump to other resultsinterest that is paid only on the original amount of money that you invested, and not on any interest that it has earned compare compound interestSee simple interest in the Oxford Advanced American DictionaryCheck pronunciation: simple interest oxfordlearnersdictionaries.com