The document was the brainchild of historian Dr George Redmonds - who collected many of the words from sources including diaries, letters, court records and early tax rolls.
Unusual words for the Yorkshire region include 'fettle', meaning to 'put in order', 'day gate' meaning 'sunset' and 'sackless', meaning 'innocent of wrong intent'.
Dr Redmonds worked tirelessly on turning his shorthand notes - some of which were decades old and held in shoe boxes - into the dictionary in an almost two year process before he passed away in 2018.
Terms in the new dictionary include 'Ginnel or Snicket' for an alleyway', 'Bray' to hit someone' and 'Brass' for money.
Ms Medcalf, project archivist at the Borthwick Institute for Archives, at the University of York, said Dr Redmonds spent more than 60 years collecting words on little postcards.
She said: "When we discovered his collection it was decided it was really too important to just stay in shoeboxes in his office.
"It is a lifetimes work and has taken around two years to turn from physical documents to our website.
"It is important because it has information about the different parts of Yorkshire.
"You can't look back in history and understand it without understanding the language those people would have used."
Ms Medcalf said she had already had feedback on users of the website.
She added: "Everybody uses language and we have had contact from the public who thanked us for solving the mystery of where certain words come from.
"There is often a debate with phrases such as ginnel and snicket and this is part of it.
"Others have said the dictionary has allowed them to relive a word from their youth or which their mother used to use.
“We hope the dictionary provides a framework for other regions to develop their own dictionary projects, as it would be really interesting to build a complete picture of the movement of old words and language around the UK.
"Perhaps we could even see a revival of some of the phrases!”
The dictionary features words that were in use between about 1100 to 1800.
Among the entries are quishing, a term for cushion, and rackan crook, a hook for hanging pots and pans over a fire.
Barnsley-born famous poet Ian McMillan, who helped launch the dictionary, said: "Sometimes Yorkshire words can just fly in the air, or end up on the edge of your ear, and the great job they've done with this dictionary is make it real, so these things are not ephemeral anymore.
"If you don't record these words then they'll go.
"Once the things that these words were about - mining, cotton, farming - start to change, and sometimes disappear, then the words will go too."
To visit the website, go to https://yorkshiredictionary.york.ac.uk/
A hard copy version of the dictionary will be published towards the end of 2019.