This dictionary encompasses over 200 words from a dozen languages. To help you in your studies, I've written a short summary of the main eight languages in the dictionary.
Ehlnofex - the language of the Ehlnofey. It is written in ALL CAPS and relies more on poetic association than literal meaning.
Aldmeri - the language of the Aldmer, the first elves. Most other languages, like Dunmeri and Nedic, stem from here. Very similar to Ehlnofex, but more stable in meaning.
Ayleid - the language of the Highland High Elves. Surprisingly different from Aldmeri, it is stylistically reminiscent of Professor Tolkien’s Quenya.
Draconic - Dragon tongue, also used for the Nordic Thu'um. Verbs have no tense and many thematically related words sound alike. Game Informer has a good summary.
Dunmeri - the language of the Dunmer, many words are similar to Aldmeri.
Jel - the language of the Argonians and Hist. It is said to be “the closest speech to thought,” and presumably relies on multiple meanings and associations.
Kothri - the language of the Kothringi, a Nedic tribe living in southern Cyrodiil. The sample we have supposedly comes from the first half of the 1st era (c.1E240-1E1200). The language shows strong Aldmeri influence.
Ta’agra - the language of the Khajiit.
Yoku - the language of Yokuda and the Redguards.
The new dictionary is laid out more like an actual dictionary. The format is pretty simple:
1 Phrases don't have parts of speech, and neither do Ehlnofex words (see linguistic notes below).
2 Some words appear in multiple languages. In such cases, the earliest identifiable source has been listed.