Kilt

A kilt is a garment worn by men of the Scottish Highlands, which first originated in the 16th century. It is a plaid skirt made of thick wool with a sash worn over one of the shoulders. It has a variety of accessories, such as the sporran (a pouch worn on a loose belt) and a knife called Sgian Dubh ("Black Knife" in Gaelic), which can be carried in public (tucked into an over-the-calf sock) when worn with a kilt.

In mainstream Smurfs media, Gutsy from the 2011 Smurfs movie is the only known Smurf character to wear a kilt.

Empath: The Luckiest Smurf stories
In the EMPATH: The Luckiest Smurf story series, Duncan McSmurf is the only Smurf in Empath's generation of Smurfs who actively wears a kilt. Unlike his father Angus McSmurf, Duncan wears his kilt over regular white Smurf pants in his normal everyday activities, as does his own son Malcolm. During more leisurely activities in the summer, Duncan may just wear the kilt by itself along with a pair of shoes or sandals. Probably due to his personal dignity, Duncan rarely wears a kilt without some sort of undergarment. (Of course, Duncan is pretty much aware of his counterpart Gutsy in a totally different story that Narrator appeared in.)

Kilts were also worn by the other male Smurfs during their time-traveling adventures in The Lost Year.

Hero: The Guardian Smurf stories
In the HERO: The Guardian Smurf story series, Hero wears a kilt as a wedding garment, while Fergus MacSmurf and his son William wear one as a standard outfit.

Glovey Story
Besides Gutsy, Hendry is another male Smurf character who wears a kilt, being the leader of a group of Smurfs in Scotland. Clumsy's namesake son also wears a kilt in his adult years.