What does the phrase "chimney sweepers" mean in London?

Depending on what literary text you are referencing, and what the context of the piece is, "chimney sweeper" may have a very literal or metaphorical meaning.

In a literal context, a chimney sweep(er) is someone who cleans chimneys as a profession. This used to be a very important job in many parts of the world. In homes which use fireplaces or wood-burning stoves for cooking and warmth, the chimney allows smoke to escape cleanly and...

Depending on what literary text you are referencing, and what the context of the piece is, "chimney sweeper" may have a very literal or metaphorical meaning.

In a literal context, a chimney sweep(er) is someone who cleans chimneys as a profession. This used to be a very important job in many parts of the world. In homes which use fireplaces or wood-burning stoves for cooking and warmth, the chimney allows smoke to escape cleanly and safely. Unfortunately, smoke carries with it all kinds of particulate and tar, which can build up inside of the chimney. If the chimney is allowed to get too dirty, it becomes a fire hazard. The chimney sweep would come in with a large brush and sweep out the insides of the chimneys. During the Victorian period, it was not uncommon for children to work as sweeps because their small bodies fit more easily down the chimneys.

In some cases, to call someone a chimney sweep implies racist sentiment. Throughout some European countries, Saint Nicholas (Father Christmas, Santa Claus) has a sidekick who is either portrayed as a chimney sweep or man of African descent. Depending on the tradition, there may be no racism implied at all, as cleaning chimneys comes with the hazard of getting a very sooty face. Many have argued over the colonialist and racist implications of the character, though, and in places like the Netherlands, to call someone "Black Pete" can be a slur. It is possible that in London, depending on the influence of culture, one might use the term chimney sweep as a racist remark.

More recently, several entries in an online slang website (which I do not feel comfortable giving you a link to) have defined "chimney sweep" as a colloquialism for either a gynecologist or proctologist. This is meant to poke fun at the professions of physicians who deal with the more tunnel-like parts of the anatomy.