I'm just off out to the Globe Theatre in London to see Richard III performed in Mandarin, part of the Globe's international season (here's a short BBC news video about it).
I don't know Mandarin, so I have been swotting up on the play and reading an annotated edition. I discovered that the word shamefaced, first recorded in the mid-16th century, was actually an etymological misinterpretation of the much older (it goes back to the earliest days of Old English) shamefast, last used, according to the OED, in the 19th century. The definition is 'bashful or modest', and was originally intended to be a positive word. Unshamefast is also in the Dictionary, meaning 'immodest'. The original meaning of fast was 'restrained', but the OED says it was a common adjectival suffix in Old English (e.g. the word handfast once meant 'espoused or betrothed', soothfast meant 'truthful' and the word steadfast dates back to OE times).