hardened chalk or soapstone used to make temporary guide marks on a garment that is being altered.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
British Dictionary definitions for tailor's chalk
pipeclay used by tailors and dressmakers to mark seams, darts, etc, on material
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