the most fundamental considerations; essentials; realities (usually used in the phrase get down to brass tacks).
Words nearby brass tacks
Origin of brass tacks
First recorded in 1895–1900
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for brass tacks
informal basic realities; hard facts (esp in the phrase get down to brass tacks)
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