Onions, in Taoism and geomantic omen, are considered to be able to ward off yin and evil spirits, and to keep the family quiet and free from ghosts. It's good to find onions, which bodes well every day. Bad things and bad luck will be washed away. Solemnly declare: the answer is for reference only, please don't be blindly superstitious.
Onion, a perennial herb of Allium in Liliaceae, is a common vegetable or condiment.