uninflected
/ˌʌnɪnˈflektɪd/adjective
1
- Grammar (of a word or a language) not undergoing changes to express particular grammatical functions or attributes【语法】（单词, 语言）无屈折变化的：
English is largely uninflected.
英语总体上无屈折变化。
2
- not varying in intonation or pitch不变音的; 无转调的：
her voice was flat and uninflected.
她的嗓音平缓稳定。