There have been many false alarms in the building recently.

She smiled false-heartedly at her ex-boyfriend.

Her false-heartedness was evident in her deceitful actions.

The falsenesses of his claims were exposed during the trial.

The falsers were exposed for spreading misinformation.

False loose smut is a fungal disease that affects cereal crops.

The false sabre-toothed cat was a nimravid.

False saber-toothed cats roamed the prehistoric landscape.

False sabre-toothed cats roamed the prehistoric landscape.

The false saber-toothed cat is an extinct species of large predatory mammal.