The Oxford English Dictionary may disappear from bookshelves as future editions may be too big to print, its publishers fear.
Only an on-line format would be practicable and affordable as the third edition is expected to be twice the size of the current version, according to its publishers.
The publishers say the third edition of the famous dictionary, estimated to fill 40 volumes, is running at least 20 years behind schedule, The Telegraph reported.
The mammoth masterpiece is facing delays because "information overload" from the internet is slowing compilers, Michael Proffitt, the OED's first new chief editor for 20 years, said.
Proffitt's team of 70 philologists, including lexicographers, etymologists and pronunciation experts, has been working on the latest version, known as OED3, for the past 20 years.
The next edition will not be completed until 2034, and likely only to be offered in an on-line form because of its gargantuan size, Proffitt told Country Life magazine.
"A lot of the first principles of the OED stand firm, but how it manifests has to change, and how it reaches people has to change," said Proffitt.
Work on the new version, currently numbering 800,000 words, has been going on since 1994, the report said.
The first edition, mooted in 1858 with completion expected in 10 years, took 70 years.