Onomasiology (from — to name, which in turn's from ὀνομα — name)'s a branch of linguistics concerned with the question "how do you express X?" It's in fact most commonly understood as a branch of lexicology, the study of words (although some apply the term also to grammar and conversation). Onomasiology, as a part of lexicology, departs from a concept (for example an idea, an object, a quality, an activity etc.) and asks for its names. The opposite approach'… (More on Onomasiology)