parallax.

An apparent change in an object’s position relative to a background when the observer’s position changes.

Use it for

Words that belong together

• stellar parallax
• parallax error

On the page

Stellar parallax helped them separate the nearby source from the distant background.

A parallax error made the pointer seem aligned until she moved her head.

Usage notes

Primary category: sci-fi. Forms: Usually uncountable; parallaxes for distinct measurements or effects. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings.