nutty slack

A pile of nutty slack at the National Railway Museum in York, Yorkshire, England, United Kingdom.

From nutty (“containing nuts”) +‎ slack.

• (Received Pronunciation) IPA^(key): /ˌnʌti ˈslæk/
• (General American) IPA^(key): /ˌnʌti ˈslæk/, [-ɾi-]
• Rhymes: -æk
• Hyphenation: nut‧ty slack

nutty slack (uncountable)

1. (British, historical) A cheap fuel consisting of slack (“coal dust”) and nuts (“small lumps of coal”); unlike other solid fuels it was not rationed during the period after World War II.
   • 1953 February 2, Gerald Nabarro, Member of Parliament for Kidderminster, “Nutty Slack”, in Parliamentary Debates (Hansard): House of Commons Official Report (House of Commons of the United Kingdom), volume 510, London: Her Majesty’s Stationery Office, →ISSN, →OCLC, columns 1460–1461:

     Mr. Nabarro asked the Minister of Fuel and Power the calorific value of nutty slack currently being marketed to domestic consumers, ration-free, by the National Coal Board, compared with normal house coals; what quantity of nutty slack is to be available, in total, during the present coal-winter; the market response to date; how much nutty slack it is estimated will be sold this winter; and whether nutty slack is to be a permanent, ration-free feature of our domestic fuel economy.

• coal dust on Wikipedia.Wikipedia
• “nutty slack, n.” under “nutty, adj.”, in OED Online ⁠, Oxford, Oxfordshire: Oxford University Press, June 2022.
• “nutty slack, n.”, in Collins English Dictionary.