Dictionary entry

Widal's

Webster's Dictionary 1913

{ Wi‐dal's″, orWi‐dal″, testorreaction } (?). [After Fernand Widal (b. 1862), French physician.] (Med.) A test for typhoid fever based on the fact that blood serum of one affected, in a bouillon culture of typhoid bacilli, causes the bacilli to agglutinate and lose their motility.