英语词源字典 - 在线词源网站

brazen (adj.)[brazen 词源字典]: Old English bræsen "of brass," from bræs "brass" (see brass) + -en (2). The figurative sense of "hardened in effrontery" is 1570s (in brazen-face), perhaps suggesting a face unable to show shame (see brass). To brazen it out "face impudently" is from 1550s.[brazen etymology, brazen origin, 英语词源]
impudent (adj.): late 14c., from Latin impudentem (nominative impudens) "without shame, shameless," from assimilated form of in- "not, opposite of" (see in- (1)) + pudens "ashamed, modest," present participle of pudere "to cause shame" (see pudendum). Related: Impudently.
talk (v.): c. 1200, talken, probably a diminutive or frequentative form related to Middle English tale "story," and ultimately from the same source as tale, with rare English formative -k (compare hark from hear, stalk from steal, smirk from smile) and replacing that word as a verb. East Frisian has talken "to talk, chatter, whisper." Related: Talked; talking.

To talk (something) up "discuss in order to promote" is from 1722. To talk shop is from 1854. To talk turkey is from 1824, supposedly from an elaborate joke about a swindled Indian. To talk back "answer impudently or rudely" is from 1869. Phrase talking head is by 1966 in the jargon of television production, "an in-tight closeup of a human head talking on television." In reference to a person who habitually appears on television in talking-head shots (usually a news anchor), by 1970. The phrase is used earlier, in reference to the well-known magic trick (such as Señor Wences's talking head-in-the-box "Pedro" on the "Ed Sullivan Show"), and to actual talking heads in mythology around the world (Orpheus, Bran).