n.an adult's imitation of the speech of a young child
同义词：baby talkbabytalk
英汉双解大词典
motherese/ˌmʌðəˈriːz/
1.
N（名词）
the simplified and repetitive type of speech, with exaggerated intonation and rhythm, often used by adults when speaking to babies 母亲式语型; 简单重复的语言类型，伴有夸张的语调和节奏，通常在成年人对婴儿讲话时使用