brown study

A state of mind, where deep but incoherent thought comes wordlessly. A lonely mental abstraction; not necessarily gloomy but often so. When you emerge from a brown study it is often difficult to remember what you have been thinking about.

Amanda looked out at the rain and the leaden sky. She was alone. At times like this she was prone to quote melancholy poetry and then fall into a brown study.

Lord Muck

A British term used to rebuke a small boy who takes favours and presents for granted without giving appropriate thanks: also used after other discourtesies. Usually used by his mother.
Lady Muck is the feminine equivalent.

Mother Alex, say thank-you when I give you your sandwiches. Who do you think you are: Lord Muck?

Mother Alice, don't just sit there like Lady Muck when you can see I need a hand with passing round the plates.

adventuress

A woman who makes her advancement in life by using questionable and amoral means. She may use financial, emotional and sexual deceits.

Adeline of Headington was a Victorian adventuress who bankrupted several prominent men. She then watched their plight with some amusement.

Bridget (Linda Fiorentino) in 'The Last Seduction' is the ultimate modern adventuress. She will murder to achieve her ends.