may·on·naise 
(m
ā′ə-n
āz
, m
āə-n
āz
′)
n. A thick dressing made of beaten raw egg yolk, oil, lemon juice or vinegar, and seasonings.
[French mahonnaise, mayonnaise, possibly from Mahón, Spanish city on Minorca captured by Louis François Armand de Vignerot du Plessis, Duc de Richelieu (1696-1788), in 1756 (the duke's chef is said to have introduced mayonnaise in honor of this victory).]