Spillover (noun)

1. An overflow or excess that goes beyond normal or desirable limits.
2. The transfer or spread of a phenomenon or condition from one area or situation to another.

Origin:

Mid 19th century: from spill + over.

Examples:

1. The spillover of water from the basin onto the floor was due to a leak.
2. The spillover of people from the overcrowded train onto the platform caused a delay.
3. The spillover of conflict from one country to another was a concern.
4. The spillover of oil from the damaged tanker into the ocean was a disaster.
5. The spillover of excitement from the concert into the streets was palpable.