the state of being subject to danger or injury
"The old bridge creaked ominously under his weight, highlighting the deep insecurity of its crumbling supports."
the anxiety you experience when you feel vulnerable and insecure
"Her constant checking of her reflection revealed a deep insecurity that made her feel exposed whenever she walked into a crowded room."
A lack of security; uncertainty.
"After hearing rumors about layoffs, a deep sense of insecurity filled his mind as he wondered if he could pay next month's rent."