Two Japanese words -- "karoshi" and "keiretsu" -- have made it into the Oxford English Dictionary for the first time.

The business-related words are among several hundred new additions to the Oxford English Dictionary Online, which is updated quarterly.

An Oxford spokeswoman said the words were included by the dictionary's lexicographers because they had been appearing frequently in the English-language media in Britain and in the rest of the English-speaking world.

The dictionary defines karoshi as "death brought on by overwork or job-related exhaustion" and keiretsu as "a hierarchy of suppliers, subcontractors, etc. owned or part-owned by a parent company which they serve."

A second, more popularly used definition the dictionary gives to keiretsu is "a conglomeration of separate businesses linked together by cross-shareholdings in one another to form a robust corporate structure, highly resistant to takeover bids or drastic losses."

In addition to the new words, the online version of the dictionary has an improved search engine, which officials say will allow, for example, subscribers to search for all the words of Japanese origin that entered the English language in the 16th century.

The first edition of the Oxford Dictionary was completed in 1928. The online version ( provides subscribers access to 20 volumes of the dictionary's second edition and three volumes of additions -- a total of approximately 500,000 words.