Insecure – 1. Not confident; uncertain about oneself 2. Not firm or fixed, or insufficiently protected
In securing (insecure) the doors of the plane, the pilot believed everything was right, but the passengers were not so confident or certain and thought they might be insufficiently protected.
Examples of insecure in a sentence (not confident)
She was insecure about her looks, but everyone else could see she was pretty.
He always seemed very confident, although he was very insecure.
She had been drawing all her life but was still insecure about her talents.
Examples of insecure in a sentence (not firm or fixed)
The stables were insecure, one strong gust of wind could cause them to collapse.
As an freelancer he was always financially insecure.
Insecure doors and windows makes it very easy for thieves to break in.