This study deals with ideophones in Sidaama. The Sidaama ideophones are uniquernfrom the other word categories in the language. They are expressive of soundrnsymb'olism in that they manifest systematic relations with meanings. They exhibitrnfeatures that. are less common in the other word classes of the language. Somernideophones display nasalization expressed via nasalized vowels. Ideophones in Sidaamarnare expressed in limited morphophonemic patterns. They have their own rules such asrnvowel harmony and sound alteration. They are commonly disyllabic and exhibit extralongrnsyllables. Furthermore, total reduplication is highly productive in ideophones.rnUnlike the other open class words in Sidaama, ideophones take little inflectionalrnaffixes. However, other open-class words can be derived from them by means ofrnaffixation, compounding and reduplication. Ideophones are syntactically associatedrnwith the auxiliary verbs / 7ass-/ 'do' and / j-/ 'say' and occur in a focused position in arnsentence which is preverbal. Sidaama ideophones have specific, expressive andrnemphatic meanings. Given aforesaid unique characteristics, Sidaama ideophones seemrnto constitute their own independent open word class