Abstract
A word can be divided into its smallest parts, bearing in mind its form and meaning. After we split the word, we get the part which is called the root. However, sometimes or rather often; a problem occurs in dividing the word in order to find its root. This is due to either sound changes in the root or the fact that it cannot be possible to establish the link between meaning of the root and the meaning of its suffix(es). The reason why the root may be unrecognizable is due to the changes in its sound or its seeming like the root of another word. Likewise, this is the reason why the root of the word kuşku (doubt) is associated with the meaning kuş ''bird'', etc. in the quest for its etymology in the Turcology literature. Aside from establishing a relative connection between kuşku (doubt) and kuş (bird) in terms of meaning, it seems like the similarity in form also contributed to this association. However, etymology is practiced primarily with meaning, rather than ''relying on the ear''. In addition to the meaning-form relationship, it has to be questioned whetherthe derivatives ofthe same root which support the existing word. Kuşku is a conceptual word, which has a higher/secondary meaning. ''Being between two things, doing something similar, considering as equal, branching'' are among its sub/first meanings. Accordingly, it is definitely possible to say that the word kuşku is derived from the verb koş-, meaning ''making equal, doing something's equal (to think); doing something similar (to think)''. While presenting the rationale for this argument, this article includes showing the parallelism found with the support from the relationship between old and new knowledge in other languages.