A person who is challenged or issued a challenge by another person, especially in sports or competition.
From challenge plus the suffix -ee (from French -é, meaning 'one who receives the action'). This suffix creates the opposite role from -er, so a challenger challenges, while a challengee is challenged.
The -ee suffix is handy for naming the person receiving an action—employee (one employed), payee (one paid), but some words like 'challengee' sound awkward, which is why we don't use it as often as we do 'challenger.'
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