diminutive formation, from Old French -ette (fem.), utilized indiscriminately in Old French with masculine form -et. As a general rule, older words lent from French have actually -et in English, while people taken in since 17c. have actually -ette. Being used with native words since belated 19c., specifically among individuals whom coin brand new product names, just who often give it a feeling of "imitation, sort of" (including flannelette "imitation flannel of cotton fiber," 1876). Additionally in terms like sermonette, which, OED remarks, "can scarcely be considered in good usage, however often met within papers."