Wiktionary
n. 1 (context uncountable countable English) A plant, ''Lepidium sativum''. 2 (context uncountable English) The pungent leaves of the plant, used in salads.
WordNet
n. cress cultivated for salads and garnishes
Wikipedia
Cress (Lepidium sativum), sometimes referred to as garden cress to distinguish it from similar plants also referred to as cress (from old Germanic cresso which means sharp, spicy), is a rather fast-growing, edible herb.
Garden cress is genetically related to watercress and mustard, sharing their peppery, tangy flavor and aroma. In some regions, garden cress is known as mustard and cress, garden pepper cress, pepperwort pepper grass, or poor man's pepper.
This annual plant can reach a height of 60 cm (~24 inches), with many branches on the upper part. The white to pinkish flowers are only 2 mm (1/12 of an inch) across, clustered in branched racemes.
When consumed raw, cress is a high- nutrient food containing substantial content of vitamins A, C and K and several dietary minerals.
Usage examples of "garden cress".
The young seedling plants of White Mustard are commonly raised in gardens for salad, the seeds being usually sown with those of the garden cress and germinating with great rapidity.