​ONOMATOPOEIA, literally the making or formation of words (Gr. ὀνοματοποιία, from ὄνομα, name, ποιεῖν, to make), hence a term used in philology for the formation of words by imitation of natural sounds, e.g. " hiss," " hush," " click." Modern philologists prefer the term " echoism," " echoic " for this process, as suggesting the imitative repetition of the sounds heard. At one time there was an exaggerated tendency to find in echoism a principal source in the origin and growth of language, ridiculed as the " bow-wow " theory of language; it is now recognized that it has played only a limited part.