From The Big Bang Theory Wiki
- Aegean – The name of a sea, actually an arm of the Mediterranean Sea, located between Greece and Turkey.
- Nabokov – Russian novelist - http://en.wikipedia.org/wiki/Vladimir_Nabokov
- MCM – Roman numeral for 1900
- Phylum – A name for one level of scientific classification of animals, between Kingdom and Class.
- Port Au Prince – the capital city of Haiti; Leonard reads the clue aloud: 'Papa Doc's capital idea'. 'Papa Doc' was the nickname of François Duvalier who was the president and dictator of Haiti from 1957 until his death in 1971.