Undesirable is an example.
Frictions
Lactose tolerance
Are all changes desirable? Clearly not. Example: "lets change the notion of educating our children, to never educating them" All changes are not desirable. Then ask: Is any change always desirable? No. Should the prospect of change be desirable? Sometimes. The answer depends on perception, intention and outcome. The only truth with almost near certainty is to state the following: Change can be desirable.
Current example
It slows it down and/or creates heat.
Friction belongs in between two contacting surfaces
Getting in or out of a bathtub.
In the operation of a seesaw, some energy is lost to friction.
To avoid frictions and also prevent from damage of an insects
Fluid friction occurs when a solid object moves through a fluid.
friction is generated when two objects are rubbing