From the perspective of Cognitive Linguistics, ground of metaphors in traditional rhetoric is ab-stracted as an ad hoc cognitive domain (ACD)—the overcharging domain that includes both the tenor and the vehicle as its domain members.Consequently, the original cross-domain metaphoric mappings are projected, via shared properties, from source domain to target domain within the same ACD.That is to say, metonymy or metonymic mechanism plays a basic role in the genesis of metaphor.Besides, considering the cognitive basis of metonymy and metaphor re...