Etymology of "catch a bosso"

Question

Reading Look to the Lady, by Margery Allingham, I came across the apparent slang "catch a bosso," used by Lugg, the Cockney manservant, at the beginning of Chapter 6:

As soon as I caught a bosso of 'im and 'is 'arem going up that street, I come up to see what the 'ell you was up to---sir.

The meaning seems clear enough---Lugg caught a glimpse of "'im and 'is 'arem"---but I'm wondering about the etymology. Is this an instance of Cockney rhyming slang and, if so, what is the origin?

I should add that Look to the Lady is set in the late 1920s or early 1930s, so this slang might be localized in both time and place.

Answer 1

Green's Dictionary of Slang has boss, "a view, or sight, of", which he suggests is derived from boss-eye, a "squinting or injured eye, or person who has one".

This is said to be derived from boss, "to make a mess of, to spoil".

The sources quoted for this are all in the 1880's, with an example from 1926, which fits quite well with your book.

Answer 2

I have heard the expression 'bosso' usually to mean an idiot, a buffoon.

1. bozo
   An incompetent person, especially in new companies. Bozos have a net negative effect on morale and profits, and everyone knows it. .

I first heard this specific meaning of "bozo" during a talk to business students by one of Yahoo's founders. .

Q: "What's the most important thing to do in order to grow your company from 10 employees to 100 or 1000?" .

A: "Get rid of the bozos. Seriously, fire them immediately."

http://www.urbandictionary.com/define.php?term=bozo