1. within a short period after this or that time, event, etc.: We shall know soon after he calls. 2. before long; in the near future; at an early date: Let's leave soon. 3. promptly or quickly: He came as soon as he could. 4. readily or willingly: I would as soon walk as ride. 5. early in a period of time; before the time specified is much advanced: soon at night; soon in the evening. EXPAND 6. Obsolete . immediately; at once; forthwith.