Lexis meaning ‘word, phrase’ (hence lexicos ‘having to do with words’) and logos

Ex. words unmanly and discouragement morphemically are referred to the same type as both are segmented into three UCs representing one root, one prefixational and one suffixational morpheme. However the arrangement and the nature of ICs and hence the relationship of morphemes in these words is different — in unmanly the prefixational morpheme makes one of the ICs, the other IC is represented by a sequence of the root and the suffixational morpheme and thus the meaning of the word is derived from the relations between the ICs un- and manly- (‘not manly’), whereas discouragement rests on the relations of the IC discourage- made up by the combination of the. prefixational and the root-morphemes and the suffixational morpheme -ment for its second IC (’smth that discourages’). Hence we may infer that these three-morpheme words should be referred to different derivational types: unmanly to a prefixational and discouragement to a suffixational derivative.
The nature, type and arrangement of the ICs of the word is known as its derivative structure. Though the derivative structure of the word is closely connected with its morphemic or morphological structure and often coincides with it, it differs from it in principle.
According to the derivative structure all words fall into two big classes:
1. simplexes or simple, non-derived words (words which derivationally cannot’ be segmented into ICs, the morphological stem of simple words, i.e. the part of the word which takes on the system of grammatical inflections is semantically non-motivated and independent of other words).
Ex. hand, come, blue, anxious, theory, public
2. derivatives(words which depend on some other simpler lexical items that motivate them structurally and semantically, i.e. the meaning and the structure of the derivative is understood through the comparison with the meaning and the structure of the source word. Hence derivatives are secondary, motivated units, made up as a rule of two ICs, i.e. binary units).
Ex. words like friendliness, unwifely, school-masterish, etc. are made up of the ICs friendly + -ness, un- + wifely, schoolmaster+-ish. The ICs are brought together according to specific rules of order and arrangement preconditioned by the system of the language. It follows that all derivatives are marked by the fixed order of their ICs.