拟态词是指用文本化的声音仿真事物特征的词汇。在东亚的语言中有大量的拟态词；非洲的语言里也有很多拟态词；在欧洲的几种主要语言里，这种词很少，并视之为一种儿语化的修辞手法。

古汉语中，落落大方的“落落”，侃侃而谈的“侃侃”，“洋洋大观”的“洋洋”都是拟态词；现代汉语里“绿油油”、“黑乎乎”、“矮墩墩”的“油油”、“乎乎”、“墩墩”也是拟态词。它们没有任何实意，只是发个音仿真事物的状态特征，字典只能解释成“形容……的样子”。

形容词作为有实意的成熟词汇，可能源于儿语式的拟态词。汉语有一个例子，“悄悄”本来是个拟态词，形容安静的样子，可是在现代汉语里的用法已经像一个独立的有实意的形容词。

Ideophones are words that evoke an idea in sound, often a vivid impression of certain sensations or sensory pe****tions, e.g. sound, movement, color, shape, or action. Ideophones are found in many of the world's languages, though they are relatively uncommon in Western languages. The word class of ideophones is sometimes called phonosemantic to indicate that it is not a grammatical word class in the traditional sense of the word (like 'verb' or 'noun'), but rather a lexical class based on the special relation between form and meaning exhibited by ideophones. In the discipline of linguistics, ideophones have long been overlooked or treated as mysterious words, though a recent surge of interest in sound symbolism, iconicity and linguistic diversity has brought them renewed attention.