sashyoudaoicibaDictYouDict
sash: The sash you wear [16] and the sash that goes in a window [17] are distinct words. The former comes from Arabic shāsh ‘turban’, and that is exactly how English first acquired it: ‘All of them wear on their heads white shashes and turbans, the badge of their religion’, George Sandys, Travels 1615. But the Arabic word also denoted a strip of muslin or other material from which such turbans were constructed, and it is that application that led towards the end of the 17th century to the current sense of the English word.

The altered form sash appeared around the same time. Sash ‘window-frame’ was originally chassis, an early borrowing of French chassis ‘frame’ (it was acquired again in the sense ‘frame of a carriage’ in the 19th century). This evolved to shashes, and in due course came to be regarded as a plural form, so a new singular sash emerged. French chassis itself goes back ultimately to Latin capsa ‘box’, source of English capsule, case, etc.

=> capsule, case, chassis
galleywest (adv.)youdaoicibaDictYouDict
indicating where something or someone is knocked, "into an extremely distressed or disabled condition," American English slang, by 1835; considered by OED to be a corruption of western England dialectal collyweston, name of a village in Northamptonshire ("Colin's West Farmstead") that somehow came to signify "askew, not right." But Farmer calls it an Americanism and goes in for it as an "indefinite superlative," and DAS also does not consider the obscure English term to be the source. Early nautical references suggest it might simply be what it looks like: a sailor's generic way of indicating something has been thrown pretty far by impact, based on galley in the "ship's cooking room" sense.
"Matter? why d--n my old shoes, Captain Williams, here is one of that bloody Don Dego's shot gone right through the galley-door, and through the side of the big copper, and knocked all the beef and hot water galley-west. ..." [N.Ames, "Old Sailor's Yarns," New York, 1835]
mouthpiece (n.)youdaoicibaDictYouDict
also mouth-piece, 1680s, "casting fitted on an open end of a pipe, etc.," from mouth (n.) + piece (n.). Meaning "piece of a musical instrument that goes in the mouth" is from 1776. Sense of "one who speaks on behalf of others" is from 1805; in the specific sense of "lawyer" it is first found 1857.