A person who becomes boggled or confused; someone who is easily bewildered or startled.
From 'boggle' (verb) + '-er' (Old English suffix denoting an agent or person who performs an action). The suffix '-er' creates a noun naming someone characterized by the verb.
The suffix '-er' is one of English's most productive tools—add it to almost any verb and you get 'someone who does that,' which is why we have boggler, walker, teacher, and thousands of others.
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