fusible metal

noun
  1. any of various alloys, as of bismuth, lead, and tin, that melt at temperatures as low as 160°F (70°C), making them useful in various safety devices.
Also called fusible alloy.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for fusible metal

fusible metal

fusible alloy

noun
  1. any of various alloys with low melting points that contain bismuth, lead, and tin. They are used as solders and in safety devices
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012