The size chart says waist 29cm, but does that refer to my waist circumference?

Let's look at the numbers first. Size M of 오비 슬릿 와이드 진 has waist 29cm, hip 91cm, front rise 20cm, thigh 52cm, and total length 104cm^[1]. Since hip 91cm is listed right next to waist 29cm, one might first guess that the two values were not measured by the same standard.

Clothing actual measurement charts are usually written by measuring each part with the clothes laid flat. Therefore, some parts are marked as only one side's width, while other parts are marked as circumference, and standards vary slightly from brand to brand. How this chart was measured is not separately stated. Thus, rather than directly matching the numbers against your body measurements, it is much more accurate to lay pants that fit you well flat on the floor, measure the same parts, and compare those values with each other. Total length 104cm is also not leg length but the length of the garment itself from the waist to the hem, so you can place it side by side with the total length of the pants you own.

There are two more pieces of information to look at together when comparing. These pants run true to size, have a moderate thickness, and have no stretch^[2]. And they are wide pants with a point slit at the waistline^[3]. hmmm, the single line saying no stretch is close to a signal to read the actual measurement chart a bit more strictly. Since there is no allowance that stretches to compensate, it is safer to decide on the more generous side for the waist and thigh measurements if they are ambiguous.