Also found in: Thesaurus.
1. Not having or using a seat belt: tests of unbelted dummies at various impact speeds.
2. Made or designed to be worn without a belt: She favors unbelted jackets.
3. Having no belt or having a belt that isn't buckled or tied: "wearing a midnight blue silk robe, unbelted, which swirled and flowed around her body" (Walter Kleine).