Dreaming of an onion can symbolize health, growth, and vitality. The meaning of this dream can vary depending on your current life situation, emotions, and experiences. Your personal feelings and experiences with onions can help you understand the significance of this dream. Ultimately, the interpretation is closely related to your individual experiences, emotions, and the circumstances you are facing in life.
From Imam Muhammad Ibn Seerin's Dictionary of Dreams According to Islamic Inner Traditions â entry "Onion" (page 311).
Eating a raw onion in a dream denotes an evil happening. If a sick person . eats a small amount of onions in a dream, it means that he will die from his illness, but if one sees himself eating a large quantity in his dream, it means that he will be cured of his illness. However, eating a green onion, or a scallion in a dream means prosperity and good health, though they will be accompanied with stress, sadness or separation from one's wife. Eating a strong smelling or a fragrant herb in a dream means contempt, loathing on the part of some members of his family toward him, or it could mean that hidden matters will finally surface. Ifsuch herbs are the type of bulbs that require skinning before eating, then they denote curiosity and eavesdropping, representing what is usually discarded. In a dream, onions for a businessman represent the element of money, and for a traveller it represents health, success and a safe return. Onions in a dream also mean distress and difficulties. Gathering onions in the field in a dream means suffering from harm caused by one's own family.
Note: Islamic dream interpretation depends on the dreamer's circumstances and state. This is a general guide drawn directly from the source book.