1. Not sure or certain; doubtful: unemployed and facing an insecure future.
2. Inadequately guarded or protected; unsafe: A shortage of military police made the air base insecure.
3. Not firm or fixed; unsteady: an insecure foothold.
4. a. Lacking stability; troubled: an insecure relationship.
b. Lacking self-confidence; plagued by anxiety: had always felt insecure at parties.