The Early Modern English Dictionaries Database
http://www.chass.utoronto.ca/english/emed/emedd.html
This is a searchable data base containing the text of sixteen 16th and 17th century English Dictionaries and could be a useful tool for unravelling some of those awkward words that turn up in old documents. It should be noted that many of the early dictionaries were foreign language dictionaries, which contained an English description of foreign words.
I decided to look up a couple of words I have come across in my Hertfordshire researches. The first was "Bever" because my great grandfather, Jacob Reynolds, ran a pack of hounds, called the "Bever Hounds" which hunted sedately with a break for a snack half way through the afternoon. The data base gives the following definition:
Comessation [(comessatio)] a late supper, inordinate or riotous eating; Iohannes Tislinus saith, it is a Bever taken after supper, or a night drinking. [Mr.] How. in his second Volumn of Letters, fol. 48. from Blount 1656
This fits in well with some other Hertfordshire uses of the word I have found, earlier in the 19th century, which included a drinking session during the harvest.
There were many definitions containing the word "firkin" including a "little but, barrell or firkin," "a kinde of rundlet or firkin or little barrell for dry things" and "A little barrell; or vessell, holding (most commonly) 36 Parisian pintes; and therefore not much different from our kilderkin, or beer-firkin of 36 quarts; also, a water bag, or budget."
If you can add to the information given above tell me.