Unsettled

To make upset or uncomfortable

"Don't unsettle the horses or they'll bolt."

To bring into disorder or disarray

Disturbed, upset.

"I was unsettled by the sudden outburst, and since I didn't know what to do I just stood there, confused."

Not in a steady condition, uncertain, subject to change.

Not populated, having no settlers or other inhabitants.

Unpaid.

"We need to settle this bill; even if you think the charge is too high we can't just leave it unsettled."