Dictionaries produced by Cowley-based publisher Macmillan Education are to stop being printed.
From next year, they will no longer appear as physical books and will be available online only.
Macmillan bosses say the online versions of its dictionary series have seen “explosive growth” while sales of the physical book have dwindled.
Publisher Stephen Bullon said: “We have seen a marked decline in sales of printed dictionaries while digital dictionaries are widespread and people are increasingly turning to online resources.
“We can provide a far more multi-functional resource online as we are free from the constraints of space and we think we can develop more powerful products.”
As well as a traditional dictionary and thesaurus, Macmillan Dictionary Online, launched in 2009, provides a blog about words and terms, a weekly newly-emerging words section and hosts the Love English Awards.
First prints of the Macmillan dictionaries came out in 2002 in collaboration with fellow publisher Bloomsbury.
The printed dictionary series is compiled by freelance lexographers around the world and printed in Hong Kong.
Mr Bullon added there would be no redundancies as a result of the move online.
But the development co-incides with the closure of the Macmillan Education office in Between Towns Road next year with the operation switching to a new central London campus for its UK publishing operations which also include Palgrave Macmillan based in Basingstoke.
Some of the 200 staff affected have already switched to London including Mr Bullon who moved to the capital three months ago. Managers say are no compulsory redundancies.
Mr Bullon added: “The message is clear and unambiguous: the future of the dictionary is digital.”