1. the occurrence of surplus liquid (as water) exceeding the limit or capacity

Similar word(s): overflow, overspill

Definition categories: event, flow, flowing

2. a final election to resolve an earlier election that did not produce a winner

Definition categories: act, election

Sentences with runoff as a noun:

- The runoff of nitrates is poisoning the lake.

- There will now be a runoff as neither front runner received more than 50% of the vote.