1. having no peak or pointed top
2. describing a cap or hat without a visor or brim

Examples

• The peakless mountain had a flat, table-like summit.
• She wore a peakless cap that fit snugly on her head.
• The peakless design of the building gave it a modern appearance.
• His peakless beanie provided warmth without blocking his vision.
• The peakless hills stretched endlessly across the prairie.
• The sailor’s peakless hat was part of the traditional uniform.