Adjective
lacking self-confidence
lacking or indicating lack of confidence or assurance
Source: WordNetA sure friend is known in unsure times. Ennius
I was thought to be 'stuck up.' I wasn't. I was just sure of myself. This is and always has been an unforgivable quality to the unsure. Bette Davis
Whatever else is unsure in this stinking dunghill of a world a mother's love is not. James Joyce
The man who voyages strange seas must of necessity be a little unsure of himself. It is the man with the flashy air of knowing everything, who is always with it, that we should beware of. Fred Hoyle
Have books ‘happened' to you? Unless your answer to that question is ‘yes,' I'm unsure how to talk to you. Haruki Murakami
We tread on unsure ground, theologically. The doctrines are still in the malleable state; what eventually evolves from them will owe its existence not to pre-eminent merit, but to the shrewdness of the compromises made by the factions. George Alec Effinger