Full text can be accessed at http://www.dbpia.co.kr/Journal/ArticleDetail/NODE01939702It can be noted in the literature that scholars seem to recognize the existence of ideophones in their languages, but no one among them finds it easy to define ideophones with precision. They have remained the subject of debate for years. For instance, in earlier works, prior to 1935, ideophones were labeled as ´interjections´, ´descriptive adverbs´, `picture words´ and `onomatopoeic adverbials´ (see Welmers 1973:460). The term ´ideophone´ seems to have been first suggested or coined by C. M. Doke (1935:118). He defined or at least described an ideophone as ´a vivid representation of an idea in sound´. On the one hand, it is maintained by some linguists that ideophones denote a complete utterance and as such have a sentence-like character. On the other hand, reports from other languages (Yoruba, Ewe etc.) disapprove that statement, showing instead that ideophones can be fully integrated into sentences, just like ordinary verbs and nouns. Yet there are some linguists who maintain that the concept `ideophone` makes sense only within the context of an individual language, while others hold the view that ideophones are a universal category. This difference of opinions, is attributable to the fact that languages vary in the manner they make use of ideophones. It is the intention of this paper to firstly, provide an overview of the attempts already made in defining the notion ideophone in some African languages. The definitions provided in the literature vary in terms of scope, depth and precision. The classical and oft-cited definitions including that of Doke (1935) and that of his later works (1967) based on his study of the Southern Bantu languages is reviewed. Other definitions include Kunene (1978) for dialects of Sotho, Moshi (1993), based on her studies of Kivunjo-Chaga, Kimenyi´s account of ideophone (from his Website) for Kinyarwanda, Kulemeka (1997) for Chichewa and finally, Dingemanse (2011) based on his study of Meaning and Use of Ideophones in Siwu. Each of these definitions emphasizes one or two salient properties of ideophones based on phonological, morphological, syntactic and semantic characteristics. Secondly, the paper outlines the main characteristics of Chasu ideophones in the light of what has been said about other African languages. Thirdly, it evaluates the contribution that ideophones from Chasu can offer to the existing studies. Fourthly, it holds the view that the definition and consequently the meaning of a particular ideophone are largely determined by its functions in the language. Finally, the paper concludes tentatively that Chasu ideophones are a lexical category distinct from verbs, adverbs and adjectives. They share some characteristics with those categories, but failed most important test of class membership.