A documented dictionary error
Dord is a documented dictionary error rather than a normal word-origin case. According to the Online Etymology Dictionary, the 1934 Webster's New International Dictionary printed dord as a physics/chemistry term for “density,” after notation intended as “D or d” was misread in dictionary preparation. Philip Babcock Gove, the dictionary's editor, published the first-hand account “The History of ‘Dord’” in American Speech 29(2), 1954, pp. 136–138. Allen Walker Read's 1978 study cites file history: the error was noticed in 1939, a plate-change/deletion order was made in 1940, and the correction was not implemented in print until 1947.
This page summarizes the cited sources. Follow each source for its full wording, notes and references.