A correspondent (from Radio 4's 'World At One') rings up to ask me about the origins of shellacking, which has received a new lease of life thanks to President Obama's use of it yesterday. How did shellac develop the meaning of 'thrashing, beating'? There's no obvious link, she said.
True. To see what happened, you have to know the intermediate stage in the development of this word. The original meaning of the verb 'to varnish with shellac' (a type of resin) is known from the late 19th century. Anything that had been 'shellacked' would have a nice rosy tinge. By the 1920s, in the USA, this effect had evidently been enough to motivate a slang use of the word meaning 'drunk'. Rosey, illuminated, and plastered show similar developments - all early 20th-century slang.
At the same time, drunks were also being described using such words as busted, bombed, crashed, and thrashed. So it's not surprising to see these words sharing their associations. The connotations of thrashing transferred to shellac, which then developed its later slang sense of 'badly beaten'. I've only every heard this used in US English - but all that is about to change. I predict it will turn up in the House of Commons within the next few days.
So, drink is the link.