Using 'dowdy' can imply a critical or negative judgment about someone's fashion sense. His dowdy attire made him stand out among the well-dressed guests.
Pro Tip 2/3
Often Subjective
'Dowdy' may vary in meaning based on personal tastes and cultural norms. What appeared dowdy to them was trendy and vintage in another community.
Pro Tip 3/3
Social Context
'Dowdy' can be inappropriate if it shames someone for their appearance; use with caution. Whispering that her outfit was dowdy was rude.