This Day in Science History - February 28 - Dord

Dord is a noun in physics and chemistry that means density. At least, that's what it meant for nearly 5 years. On February 28, 1939, the word 'Dord' was discovered to be an error in the second edition of Webster's New International Dictionary published in 1934. Dord is an example of a ghost word, or a word that was never actually used, but appeared in dictionaries.

The first edition of this dictionary had common abbreviations listed together with words alphabetically. The second edition would move the abbreviations to the back in their own special section. The the card for the abbreviation 'D or d' for density went into the wrong pile and was mistakenly combined into 'Dord'.