| rotation | การหมุน |
| rotational slide | การวิบัติลาดดินแบบเลื่อนหมุน |
| rotational spring support | ที่รองรับชนิดสปริงหมุน |
| rotational stiffness | สติฟเนสเชิงหมุน |
| Degree of Freedom: | (english) A displacement quantity which defines the shape and location of an object. In the two dimensional plane, a rigid object has three degrees of freedom: two translations and one rotation. In three dimensional space, a rigid object has six degrees of freedom (three translations and three rotations). |
| Displacement: | (english) A change in position. A displacement may be a translation a rotation or a combination of those. |
| Fixed support: | (english) In two dimensions, a fixed support restrains three degrees of freedom: two translations and one rotation. |
| Moment: | (english) The resultant of a system of forces causing rotation without translation. A moment can be expressed as a couple. |
| Pin connection: | (english) In two dimensions, a pin connection restrains two translation degrees of freedom but does not restrain rotation. Since the rotation degree of freedom is unrestrained at a pin connection, it transfers no moment. |
| Pin support: | (english) In two dimensions, a pin support restrains two translation degrees of freedom but does not restrain rotation. When considering reaction forces, a pin support is usually considered to have two force components: one each about the x and y axes respectively. |