Binoculars are two small telescopes joined for looking at distant things. A pair of binoculars, look through binoculars, eight by forty binoculars.
The two numbers on them mean magnification and the width of the front lens in millimetres, and the second decides brightness. Beyond about ten times, shake makes them unusable without a support. The word is always plural.
1nounbinocularsTwo small telescopes joined for viewing at a distance.
“She watched the birds on the lake through a pair of binoculars.”
binoculars is an instrument.
Short for binocular glass, from Latin bini, two together, plus oculus, an eye.
Abbreviation of "binocular glass".
Etymology from Wiktionary, CC BY-SA