greenlit

Greenlit means "give permission to proceed" and is typically used in film and television. Its use is predominantly in North American English.

Electrolysis

Electrolysis is chemical decomposition produced by passing an electrical current through a liquid or solution containing ions (known as electrolyte).

The word was introduced by Michael Faraday in 1834 from the Greek word "elektron" (amber) which has been associated with electrical phenomena since the 17th Century.

ahistorical

The word ahistorical means lacking historical perspective or context.

The Google ngram viewer shows this is a relatively modern word.

The Black Mountains

The Black Mountains (Y Mynnyd Du) are a group of hills on the England-Wales border. 

The Llanthony Priory is in the area. It is a partly ruined Augustinian priory in the Vale of Ewyas (at the head of the Vale is the Gospel Pass, reputed to be named after the time in the 12th Century when the Third Crusade passed through the area preaching and fund-raising). Norman knight William de Lacy founded a hermitage here.

It is the Easternmost part of the Brecon Beacons National Park.

Hyphens versus Dashes

A hyphen is a short -; joining words e.g. well-known, long-term.

An en dash (-) is slightly wider, showing ranges e.g. 10-20, London-Paris..

The em dash is long, and used for emphasis and breaks in thought e.g.  "Dishes and dusting --- all done now."  It is used in creative writing and journalism.

London's Waterloo & City Line

The Waterloo & City line is the shortest line on the London Underground, running only 2.37km entirely between Waterloo and Bank Stations enabling commuters from South West London to get into the City quickly. 

It is nicknamed "The Drain".

Bank station is North East of Waterloo, and the Waterloo & City line has to cross the River Thames. It travels under Ludgate Hill.

Monument

London's Monument is a monument to the Great Fire of London in 1666. 

It was designed by Sir Christopher Wren.

It is next to London's Monument underground station, which is on the underground's Circle and District lines (yellow and green lines respectvely). It is connected (walking distance) to Bank station which is on the Northern Line, as well as Central, DLR and Waterloo & City lines.

It is near Pudding Lane, which is one of the world's first one-way streets. An order mandating one-way cart traffic was issued in 1617.