Having eyes that bulge or stick out prominently; looking surprised with wide-open eyes.
From 'bug-eye' (a boat with a bulging appearance, or eyes that bulge) plus '-ed' (past tense/adjective suffix), derived from the bulging appearance.
The expression 'bugeyed' became slang for extreme surprise across America, especially because wide-eyed shock is universally readable in human faces across all cultures.
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