IPA: /bɪˈnɒkjʊləli/
KK: /bɪˈnɑːkjʊlərli/
In a way that involves the use of both eyes together to see things clearly and in depth.
The birdwatcher observed the rare species binocularly to appreciate its details.
Binocularly → It is formed from "bi-" (meaning two) and "ocular" (from Latin "ocularis", meaning related to the eye). The suffix "-ly" (meaning in a manner) indicates the manner of using both eyes. Thus, "binocularly" means in a manner that involves both eyes.
Think of using 'two' ('bi-') eyes ('ocular') to see something clearly — that's what binocularly means.