Is paretymology (rather than folk etymology) mostly folk, phonological, sporadic, marginal, non-functional? In truth, this is a phenomenon with multi-layered systematicity and productivity, of a semantic origin and a psycholinguistic and sociolinguistic perspective. Although its study has so far focused on the role of phonology and semantics and the morphological function may be essentially secondary, that is the result of processes at other levels, it is nevertheless significant, rather systematic and relatively predictable; it is, furthermore, connected with both segmental and structural changes. Morphological interventions are mainly analogical and artificial and can lead to a continuum of variation in the morphosemantic and structural integration of paretymological bases. This distinguishes between natural-like formations, unsuitable for synchronic study due to segmental and structural failures and/or lexicalization, one the one hand, and recognizable ones, on the other, provided that the paretymological effect is clarified.