stud

A male animal, particularly a horse, kept for breeding purposes.

"The champion stallion was a valuable stud."

A small, often decorative, knob or fastener, especially on clothing or tyres.

"He fastened his shirt with a metal stud."

An attractive man considered virile and sexually appealing.

"She thought he was a real stud."

To decorate, equip, or strengthen something with studs or similar projections.

"The belt was studded with silver."