noun
110 (police emergency number in Japan)
Refers specifically to the police emergency telephone number in Japan, equivalent to 911 in the US.
事件があったら、すぐ１１０番に電話してください。
If something happens, please call 110 right away.
noun or participle which takes 'suru', intransitive verb
call 110; call the police
Used as a suru-verb meaning to dial the police emergency number. Intransitive.
不審な人を見かけたので、すぐに１１０番した。
I saw a suspicious person, so I called 110 immediately.