Scope Focus Terminology?

[Redwing]

I have a Leupold Vari-XIIc with the adjustable objective. The AO is sticky and doesn't move as smoothly as I believe it should, particularly at the extreme ends of the adjustment range. There is a term for this, but I can not remember what the term is. Can anyone help me out, please?

Thanks.

 

[4ester]

Paralax adjustment

 

[Redwing]

I wasn't being clear. I'm asking for the term that describes the fact that the scope controls are not translating exactly and immediately to the internal optical adjustments.

Paralax adjustment

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