Attractively unusual or old-fashioned.
When quaint meant capable
Latin
cognitus
‘known, approved’
into Old French
Old French
cointe, queinte
‘knowledgeable, well-informed; clever; arrogant, proud; elegant, gracious’
into Middle English
Middle English
cointe
‘cunning, artful, ingenious; proud’
became English
English
quaint
‘unusual or old-fashioned but charming or agreeable’
Quaint once meant expert or skilled. Middle English queinte or cointe came from an Anglo-French word for cleverness or expertise, ultimately linked to Latin cognitus and knowing.
Obsolete sense 3 and the first-use record establish expert/skilled as earliest recorded; Word History supplies the French and Latin ancestry.
Today’s old-fashioned charm is far from the older compliment to someone’s ability.