• proficient (Merriam Webster)
• cumulus (Dictionary.com … maybe)
• insuavity (Worthless Word for the Day)

… on the Latin side:

https://twitter.com/#!/latinwordaday/status/204712887435014144
https://twitter.com/#!/LewisandShort/status/204589638118158336

… and the Greek:

https://twitter.com/#!/LiddellandScott/status/204588826314817536

• belabor (Dictionary.com)

• diptych (OED)

… and the Latin Words of the Day (doing some source adjusting and reorganizing here):

https://twitter.com/#!/latinwordaday/status/204312611565740033

https://twitter.com/#!/latinlanguage/status/204362602904690688

• phatic (Dictionary.com)

• sibilate (OED)

… and the Latin Word of the Day:

• eventum (Transparent Language)

… and dead guys tweeting:

https://twitter.com/#!/LiddellandScott/status/203589788127858689

https://twitter.com/#!/LewisandShort/status/203591200454877185

• omphalos (Dictionary.com)
• vicious circle (Wordsmith)
• sororal (OED)

… and the Latin Word of the Day:

• iucundus (Transparent Language)

… dead guys tweeting:

https://twitter.com/#!/LiddellandScott/status/202811938474962944

https://twitter.com/#!/LewisandShort/status/202814843890311170

• intromit (Dictionary.com)
• triangulate (Wordsmith)
• cognoscenti (OED)

… and the Latin Word of the Day:

• oboedire (Transparent Language)

… dead guys tweeting:

https://twitter.com/#!/LiddellandScott/status/201725136607518720

https://twitter.com/#!/LewisandShort/status/201711400589078529