Kibosh

When people put the kibosh on a plan, they shut it down.
The word can be a verb, but it more often is a noun.
Its earliest known printing was in 1826.
Since then, it’s had a lot of etymologists transfixed.

Some venture that it’s Yiddish, from the Hebrew for “subdue,”
But no one’s found a Yiddish source that they can trace it to.
Some look to Turkish bosh, describing empty, worthless stuff,
As used at times in English. That’s not evident enough.

There also is caidhp bháis, a term from Gaelic that referred
To hoods for executioners or pitch-caps (what a word),
The latter being filled with boiling tar to put on heads,
But Irish didn’t use it as a metaphor we’ve read.

In heraldry, an animal caboched displays no neck,
As if cut off quite neatly (from the French as we’d expect).
One scholar thought a kibosh was a foot-long iron bar
To smooth and soften leather. That idea has not gone far.

The current favored theory is the kurbash, meaning “lash”
In Arabic and Turkish, for a penalizing thrash.
Some immigrants in London taught the British lower classes.
From there, it’s gotten popular with English-speaking masses.