Taking its name from Henry Peacham's 1593 caution that "there be no unclean or unchaste signification contained in the Metaphor," "Unchaste Signification" explores rhetoricians' efforts to regulate the intercourse between what Peacham calls a word's "proper signification" and its "signification not proper, but yet nigh and like." The attempts, integral to classical and Elizabethan philosophies of metaphor, to control metaphorical discourse by prohibiting unchaste signification belie the fruitful and potentially unruly nature of metaphorical utterances, a nature vividly revealed in Shakespeare's plays. "Unchaste Signification" surveys how philosophers from Aristotle to Paul Ricoeur discuss the tension inherent in metaphor between the need for difference, distance, and interchange and the need for likeness, proximity, and containment. Metaphor's dual nature, the very source of its fecundity, also is the source of the anxiety it provokes. Just as a man who fears an unchaste wife imagines a strange child could be transported into his home, escape his notice, and usurp his name and property, so the speaker who fears unchaste signification imagines that a strange word will be transported into his semantic domain, escape notice, and usurp proper meaning. But, as Aristotle describes, metaphors are most powerful when they beget new, adulterous meanings while escaping detection---when an "alien term" is transported without an auditor's full awareness. Shakespeare's plays reveal that a metaphor's power is closely linked to the possibility that during metaphorical transport the alien name might escape and become, as it were, a resident alien in a speech community. Because in drama a fictional speech community's discourse is scripted by a playwright but not, unlike lyric or epyllion, managed by a narrator, "Unchaste Signification" focuses on the unruly fecundity of metaphor in Shakespeare's plays. Close analysis of 'Titus Andronicus, Othello, King Henry IV Part 1', and 'Hamlet' provides the opportunity to understand various aspects of metaphoric performance, including the sacrificial nature of metaphor, the special power metaphors have to import discourses into speech communities, the carnivalesque qualities of metaphor, and the ghostly power dead metaphor has to haunt living speech. (Dissertation Abstracts)