Definition

A device that helps to change the focus of an optical instrument, like a telescope, to make images clearer.

Example

The astronomer adjusted the focuser to get a better view of the stars.

Conversation

Have you ever used a telescope before?

Yeah, but I struggled with the focuser a bit.

The focuser can be tricky; it took me a while to get the hang of it.

For sure! Once you learn how to use it, the view is amazing.

Synonyms & Antonyms

Root Explanation

Focuser → It is formed from "focus" (from Latin *focus*, meaning hearth or center) and "-er" (meaning a person who). A focuser is a person or device that brings something into focus or centers attention on a particular point.

Memory Tip

Think of someone or something that helps to 'center' or 'bring into focus' — 'focus' means center, and '-er' indicates a person or thing that performs an action.

Visually Confused Words