Longman Dictionary of Contemporary English - insecure

~ adj 1 not feeling at all confident about yourself, your abilities, your relationships etc  (I'd only just started at university and I still felt very shy and insecure.) 2 a job, investment etc that is insecure does not give you a feeling of safety, because it is likely to be taken away or lost at any time  (Running a small business is a very insecure occupation.) 3 a building or structure that is insecure is not safe, because it is likely to fall down - insecurity n  (Student teachers often suffer from a great sense of insecurity.) - insecurely adv