1. Of a liquid, to flow out of a container or over some barrier and into something or some place else. Don't fill the casserole dish too high, or some will spill out into the oven while it's cooking. The floodwaters rose above the embankment and spilled out into the adjacent fields.

2. To go beyond the borders or parameters of something and into something else, especially due to growing too large in size, amount, or scope. The protests outside the central bank began growing so large that they eventually spilled out into the entire financial district. So many people turned up to the bar for Mary's birthday that we all started spilling out into the streets.