IPA: /məˈnɒkjʊləli/
KK: /məˈnɑːkjələrli/
In a way that involves using only one eye.
He observed the distant object monocularly to get a clearer view.
Monocularly → It is formed from "mono-" (meaning one) and "ocular" (from Latin "ocularis", meaning related to the eye) and the suffix "-ly" (meaning in a manner). The word "monocularly" means in a manner related to one eye or using one eye.
Think of using 'one' ('mono-') eye ('ocular') to remember that 'monocularly' refers to seeing or observing with one eye.