Recent issues in diachronic lexical semantics have shed new light on an old-fashioned linguistic discipline, i.e. onomasiology. This is less surprising when one is aware of the fact that, in their groundbreaking essay on metaphor, Lakoff and Johnson (1980) have rediscovered the existence of metaphorical schemas, the so-called “conceptual metaphors”, such as linguistic concepts are containers, argument is war etc., which assemble words and idioms having a common conceptual source and a common conceptual goal. As we will see below, this approach is already halfway towards cognitive onomasiology. Furthermore, cognitive linguistics is grounded on assumptions about language quite similar to those of onomasiology (see section 3). One of the aims of the present paper is to discuss the potential of modern onomasiology in light of cognitive linguistics. The second aim is to develop a framework of diachronic cognitive onomasiology. It will be shown that both, onomasiology and cognitive linguistics, reveal their full explanative power from a diachronic perspective.