The particle's properties were unobservable with the available equipment, leaving scientists to rely on indirect measurements.

Philosophers often debate the nature of the unobservable in metaphysics.

Researchers proposed a model to estimate unobservables from the observed data.

The unobservableness of the tiny particles frustrated the researchers attempting to measure them.

The hacker modified the code unobservably to avoid detection.

The unobservance of safety protocols at the construction site led to a preventable accident.

The unobserving security guard missed the suspicious package by the bench.

The unobserved butterfly emerged from the chrysalis at dawn, surprising the researchers.

She left the party unobserved, slipping into the night without saying goodbye.

The unobservant waiter failed to notice the spilled drink until customers pointed it out.