What is "undervote"

n. 1 A vote that has been cast but that shows no legally valid preference for a candidate in an election. 2 The number of such votes in an election. vb. (context politics English) To spoil a ballot by marking it for fewer choices than mandated by the rules.

An undervote occurs when the number of choices selected by a voter in a contest is less than the minimum number allowed for that contest or when no selection is made for a single choice contest.

In a contested election, an undervote can be construed as active voter disaffection - a voter engaged enough to cast a vote without the willingness to give the vote to any candidate.

An undervote can be intentional for purposes including protest votes, tactical voting, or abstention. Alternately undervotes can be unintentional and caused by many factors including poor ballot design.

Undervotes combined with overvotes (known as residual votes) can be an academic indicator in evaluating the accuracy of a voting system when recording voter intent.