A cap with a flat circular top and a visor WordNet 3.0 & Open English WordNet

The kepi is a cap with a flat circular top and a peak, or visor. Wikipedia

The peaked cap, peaked hat, service cap, barracks cover or combination cap is a form of headgear worn by the armed forces of many nations, as well as many uniformed civilian organisations such as law enforcement agencies and fire departments. Wikipedia

Type of cap. Wikipedia Disambiguation

Flat circular cap with a visor Wikidata

Form of uniform headgear with a short visor, crown, band, and insignia Wikidata

A cap with a flat circular top and a visor, particularly associated with French uniforms. Wiktionary

Cap with a flat circular top. Wiktionary (translation)