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

Ex. The derivational suffix -ic for example performs both functions in words like historic, economic, classic as it is applied to bases history-, economy-, class- and forms stems of words of a different part of speech. But the same suffix -ic in public, comic, music performs only its stem-building function shaping in this case a simple stem.
Besides, the non-derivational affixes shape only simple stems, for example, the morpheme -id in stupid, rapid, acid, humid; the morpheme -ish in publish, distinguish, languish. It follows that non-derivational morphemes are not applied to stems, but only to root-morphemes or morpheme sequences.
Semantically derivational affixes are characterised by a unity of part-of-speech meaning, lexical meaning and other types of morphemic meanings unlike non-derivational morphemes which, as a rule, lack the lexical type of meaning.
Ex. Prefixes like en-, un-, de-, out-, be-, unmistakably possess the part-of-speech meaning and function as verb classifiers when they make an independent IC of the derivative, e.g. deice, unhook, enslave.
1) The lexical (denotational) meaning of a generic type proper mostly not to an individual affix but to a set of affixes, forming a semantic subset such as, for example, the meaning of resemblance found in suffixes -ish, -like, -y, -ly (spiderish, spiderlike, spidery); the causative meaning proper to the prefix en- (enslave, enrich), the suffixes –ise (-ize), -(i)fy (brutalise, formalise, beautify, simplify, etc.); the meaning of absence conveyed by the prefix un- and the suffix -less; the meaning of abstract quality conveyed by the suffixes -ness, -ity, etc.
2) On the other hand derivational affixes possess another type of lexical meaning — an individual meaning shared by no other affix and thus distinguishing this particular affix from all other members, of the same semantic group. For example, suffixes -ish, -like, -y all have the meaning of resemblance, but -like conveys an overall resemblance, -ish conveys likeness to the inner, most typical qualities of the object, -y in most cases conveys likeness to outer shape, form, size of the object. Derivational affixes semantically may be both mono- and polysemantic.


Semi-affixes:
There is a specific group of morphemes whose derivational function does not allow one to refer them unhesitatingly either to the derivational affixes or bases. In words like half-done, half-broken, half-eaten and ill-fed, ill-housed, ill-dressed the ICs half- and ill- are given in linguistic literature different interpretations: they are described both as bases and as derivational prefixes. The ICs ill- and half- are losing both their semantic and structural identity with the stems of the independent words. These morphemes that are changing their class membership regularly functioning as derivational prefixes but still retaining certain features of root-morphemes. That is why they are sometimes referred to as semi-affixes. To this group we should also refer well- and self- (well-fed, well-done, self-made), -man in words like postman, cabman, chairman, -looking in words like foreign-looking, alive-looking, strange-looking