To make someone into a dandy or to cause someone to behave like a dandy; to dress or groom excessively.
From 'dandy' plus the verb-forming suffix '-ize' (meaning to cause to become or to treat as), following the pattern of similar English verbs.
The verb 'dandyize' captures the 19th-century anxiety about men becoming 'too feminine'—it was often used mockingly in social criticism and newspaper satire.
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