I think of dapper as suit and tie, hair nicely combed..and sophisticated in speech and manner

Likewise, Carolyn (pleased to meet you by the way )
Interesting that the meaning appears to have carried all over the world so consistently, as I'd always thought the term fairly Britlish.

We'd talk about a "dapper gent" - always being someone wearing a suit (or well-matched jacket and trousers) and tie. Definitely an exquisite dress sense; also an implication of small & neat (ties in with Hev's dictionary definition).

You don't get young men referred to as "dapper" much. Suppose very few young men wear suits all the time, which is requisite of the label. Even older men have generally become more laid-back these days. Suppose dapper gents are a dying breed.