Dylan Thomas cuddles penguins. Pass it on...

As the Oxford English Dictionary relaunches online this week, its attempts to uncover "the first known use of every sense of every word in the English language" will soon be much easier to scrutinize. The BBC today examines the role that the Welsh language played in the development of English, with the poet Dylan Thomas alone contributing 635 entries to the lexicon according to Edmund Weiner, deputy editor of the OED.

"His rich use of language has resulted in being acknowledged as the source of words and phrases such as 'moochin', a difficult or disagreeable person.

"The term to 'prodnose', meaning to pry or be inquisitive, is taken from Quite Early One Morning."

Professor John Koch of the University of Wales Centre for Advanced Welsh and Celtic Studies in Aberystwyth says it shouldn't surprise anyone that the Welsh have given the English language the terms for "penguin" and "cuddling." While commonly considered a Germanic language, English behaves in unusual ways that can't be attributed to Germanic or Romance languages.

"There has been an underestimation from the beginning of the Welsh component in English," he said. "It probably isn't massive like that of French or Latin. It's more under the surface."

Prof Koch said there were historical and political reasons behind the lack of credit given to the influence of Welsh.

He explained: "In the universities in which people studied the language most people who compiled the dictionaries in the first place did not know a lot about Wales, so it would not have been something they looked for."