From Longman Dictionary of Contemporary Englishcresscress /kres/ noun [uncountable] 
HBPDFa small plant with round green leaves that are eaten raw → mustard Sprinkle some finely chopped cress over the top.
HBPDFa small plant with round green leaves that are eaten raw → mustard Sprinkle some finely chopped cress over the top.Examples from the Corpus
cress• You could also sow seeds, such as mustard and cress, in the pot and see if the woodlice eat the seedlings.• Cotton Wool garden: Mustard and cress seeds grow readily on damp cotton wool.• To serve; sprinkle with mustard and cress.• A summery variation is to add finely chopped cress.• Risk of Salmonella in undercooked eggs, bacteria in cress.• Land cress, a dry-land watercress, should be sown in August outdoors, or in modules for transplanting later.Origin cress Old English cærse, cressa 