999

• nine nine nine, triple nine

Established in the United Kingdom as the first emergency service number in the world, initially chosen because of its suitability at a time of rotary-dial telephones.

• (Received Pronunciation) IPA^(key): /naɪn.naɪn.naɪn/, /trɪpəl.naɪn/, /naɪnz/

999

1. The telephone number for emergency services in the United Kingdom, Ireland, Hong Kong, Macau, Malaysia, Bangladesh, Burma, Bahrain, Qatar, the UAE, Kenya, Uganda, Zambia, Zimbabwe, Ghana, Sudan, South Sudan, Sierra Leone, Guyana, Antigua and Barbuda, Saint Lucia, Saint Vincent, Dominica, Kiribati, Samoa, the Solomon Islands, and the Seychelles.
   • 2006 Feb. 3, Graham Linehan, The IT Crowd, Season 1, Episode 2:

     I don't know why they couldn't just keep it as it was! How hard is it to remember 911?
     You mean 999...
     I mean 999!
     That's the American one!
     Yeah!
     You berk.

   When you call 999 in the UK, the operator usually answers the phone with "Emergency. Which service?"

2. The telephone number for law enforcement in Singapore, Lebanon, Saudi Arabia, Eswatini, Botswana, Tanzania, Mauritius, and Trinidad and Tobago.
3. The telephone number for firefighting assistance in Malawi and Tonga.
4. The telephone number for ambulance services in Poland.

999 (uncountable)

1. (UK, Ireland, Hong Kong, Singapore, colloquial, metonymically) Emergency services; emergency service personnel.