Boyish doesn't always mean young; it can describe a grown man with youthful traits. The actor retains a boyish enthusiasm that endears him to fans of all ages.
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Emotional Appeal
Certain 'boyish' qualities, like innocence or openness, are often seen positively. His boyish grin instantly disarmed the tough crowd.
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Cultural Perception
'Boyish' may imply different qualities in various cultures, such as courage or playfulness. In many stories, the hero often exhibits a boyish sense of adventure.