tallow

　Waste coffee grounds will be used to help power some of London's buses from Monday, it has been revealed.
　A biofuel created by blending oil extracted from coffee waste with diesel is to be added to the public transport fuel supply.
　Technology firm bio-bean says it has produced enough coffee oil to power one bus for a year.
　Transport for London (TfL) has increasingly turned to using biofuels to reduce transport emissions. ...
　Biofuel made using waste products such as cooking oil and tallow from meat processing is already used in many of the capital's 9,500 buses.
　However, this is thought to be the first time a coffee-derived biofuel has been added to London's public transport system. (Skip the rest)

http://www.bbc.com/news/uk-england-london-42044852

　今回取り上げる語は、tallow /tˈæloʊ/ です。まず意味を確認します。『新英和大辞典』(第六版、研究社)をみると、「(1)獣脂、(2)牛脂、(3)油脂状の物質、(1)...に獣脂を塗る、(2)肥やす、(3)獣脂を生じる」とあります。
次に語源を確認します。Oxford Dictionary of English (2nd Edition Revised)をみると、“Middle English: perhaps from Middle Low German; related to Dutch talk and German Talg” とあります。
　最後に類語の確認です。tallow と比較するものとすれば、lard が挙げられます。日本でも生活の中で聞かれる言葉ですが、両者の違いはなんでしょうか。同書で定義を確認すると、“fat from the abdomen of a pig that is rendered and clarified for use in cooking “ とあります。なので、両者の違いは「肉種」ということになります。(OkaUchi)