tartare sauce

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A sauce made from mayonnaise and a chopped mixture of pickled gherkins, capers, olives and shallots; traditionally served with fish or other seafood.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun mayonnaise with chopped pickles and sometimes capers and shallots and parsley and hard-cooked egg; sauce for seafood especially fried fish