a nut that serves to condense packing and so to tighten its seal.
What Does 🌰 Chestnut Emoji Mean?The chestnut emoji is sometimes referred to as the raisin emoji because it is so often mistaken for one—especially on small screens and on digital platforms where the nut is very dark brown.
Also called packing nut.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for packing nut
a large nut that is tightened to compress the packing in a stuffing box
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