BY DARRELL HARTMAN

There's a new style announcing itself in men's footwear that's all about having it both ways: the sneaker-boot.

Are they for men or boys? For work or play? Modern man's dress-code distinctions have blurred, and as a result, hybrid footwear is becoming a signature of contemporary style.

"You're seeing an interplay of more rugged or more formal shoes merged with casual ones—and the reverse of that, where casual and rugged shoes are becoming more formal," said Eddy Chai, co-owner of Odin, the New York menswear boutique.

The dictates of weather are out the window, Mr. Chai added. "Boots in the ...